With their fishermen at risk of being shot at by the Israeli navy, Palestinians in the Gaza Strip are finding new ways to supply the blockaded territory with a staple that is in short supply.

Seafood is coming into the Mediterranean enclave through tunnels from Egypt and fish farms are starting to fill a supply gap resulting from restrictions that stop fishermen from venturing more than 3.4 miles (5.5 km) from the coast.

The emergence of new ways of supplying seafood highlights the ever deepening impact of a blockade that controls land, air and sea access to Gaza, ruled by the Hamas Islamist group.

Israel says the blockade aims to prevent Hamas, which is hostile to the Jewish state, acquiring weapons or materials that could be used for military purposes.

For the majority of Gaza's population of 1.5 million, the result has been increasingly miserable living conditions, while Hamas's grip on power since 2007 shows no sign of weakening.

The group controls the tunnelling businesses which have for more than three years been a supply route for everything from cement to electrical goods and now, fish.

Gaza's fishermen, once allowed to sail up to 12 miles from the coast, risk having their boats confiscated if they go too far out. Several have suffered bullet wounds in confrontations with Israeli patrol vessels enforcing the embargo.

The current fishing limit has been in place since January, 2009, according to the U.N. Office for the Coordination of Humanitarian Affairs.

FISH FARMS

In Rafah, at the southern tip of the Gaza Strip, a masked man emerged from the mouth of a tunnel carrying a box of fish packed in ice. Anxious not to be identified, he would not speak to the media because of the dangers associated with an increasingly risky business.

The Israeli military launches regular airstrikes on areas where it believes Hamas is using the tunnels to bring weapons into Gaza. Egypt, which has a strained relationship with Hamas and a peace treaty with Israel, is building an underground barricade on its side of the border to thwart the tunnelers.

Bringing fish through the tunnels from Egypt is not as profitable as supplying other goods, said Suleiman Itta, a fish monger who has started buying fish that come to Gaza that way.

Quality can also be a problem.

"Sometimes the fish arrives almost two-thirds fresh," he told Reuters. "We bring it from Egypt because of the lack of fish here," added the father of eight.

With their own catches becoming ever more meagre, Gaza's fishermen have found another way of bringing fish ashore. They rendezvous at sea with their Egyptian counterparts and buy from them, sometimes venturing further than allowed by Israel.

"We cross the line. Most if not all fishing boats do that, and yes, it is risky but we go to buy," fisherman Ashraf Assaeedi said.

In Beit Lahiya in the northern Gaza Strip, Zeyad Al-Attar is farming fish in tanks. "We have resorted to this kind of work because of the lethal siege. We produce 70 tonnes every six months," he said.

But restaurant owner Ahmed Abu Haseera does not buy from the farms. His clients prefer fish supplied the traditional way.

"Clients do not like it. But what can we do? Things are difficult. One day we have fish and the next we don't," he said.

Israel will free 20 Palestinian women from jail as early as Friday in exchange for a videotape from Hamas proving an Israeli soldier held in the Gaza Strip since 2006 is alive, officials on both sides said on Wednesday.

Egyptian and German mediators are continuing to work on a final deal to swap the soldier, Gilad Shalit, for hundreds of Hamas prisoners. The negotiations are part of international efforts to ease Israel's blockade of the Hamas-run Gaza Strip.

"It is important for the entire world to know that Gilad Shalit is alive and well and that Hamas is responsible for his well-being and his fate," Israeli Prime Minister Benjamin Netanyahu said in a statement.

Shalit, now 23, was spirited into the Gaza Strip by Islamist militants who tunneled into Israel three years ago in a raid in which two Israeli soldiers and two of the attackers were killed.

An Israeli official said the handover of the 20 women and the tape should take place on Friday, at the end of a two-day period when Israeli citizens can appeal in court against their release, an Israeli official said.

He added that a German mediator had already seen the video and believed it genuinely showed Shalit during recent weeks -- and certainly after Israel's offensive in Gaza in December and January in which some 1,400 Palestinians were reported killed.

The video lasts about a minute, said a spokesman for the Popular Resistance Committees, one of the Hamas allies that took part in the raid in which Shalit was captured.

"It shows Shalit alive and moving," the spokesman, Abu Mujahed, said.

Announcement of the pending exchange was the first major sign of progress in efforts to put together a deal between Israel and Hamas Islamists.

"This is a humanitarian gesture," said an Egyptian security source close to the mediation efforts Cairo has been pursuing.

But an Israeli official cautioned that "lengthy and difficult negotiations" were still ahead before a final deal could be reached.

Public pressure has been mounting on Netanyahu to win freedom for the bespectacled soldier, who also holds French citizenship, in a deal that could involve the release of Hamas militants behind attacks that have killed Israelis.

Palestinians view brethren held in Israeli jails as heroes and a widescale release of prisoners in exchange for Shalit would be a boost for Hamas, an Islamist group opposed to peace with Israel.

Only one of the women, who was to be released along with her child, was from Gaza, Hamas officials said. The other 19 were from the Israeli-occupied West Bank, where Hamas's secular rivals from President Mahmoud Abbas's Fatah party hold sway.

Israeli officials said none of the women had been directly involved in killings and none was serving a sentence of longer than two years.

A spokesman for Hamas's armed wing, Abu Ubeida, told a news conference in Gaza that four of the women to be released were members of Hamas, while five were members of Fatah. Three more were members of Islamic Jihad and the rest from other groups.

Shalit has not been visited by the International Committee of the Red Cross and only a few letters and an audio cassette from him have been sent to his family, which has waged a vocal campaign to get him freed.

Israel holds more than 10,000 Palestinians in its jails. Hamas is negotiating for the release of hundreds of its members. (Writing by Alastair Macdonald and Jeffrey Heller, Additional reporting by Jeffrey Heller and Ari Rabinovitch in Jerusalem, Editing by Mark Trevelyan)

Explosions at two sensitive sites in the Gaza Strip [ID:nLU529969] have prompted speculation on Sunday that they were the work of al Qaeda-aligned radicals opposed to the Palestinian enclave's Islamist rulers Hamas.

Here are comments on key questions about the incidents:

WHO WAS BEHIND THE BOMBINGS?

No credible claim of responsibility has been made.

Since Hamas seized control of the Gaza Strip in June 2007 by routing secular forces loyal to Palestinian President Mahmoud Abbas, the Islamists have tended to blame occasional bombings and other attacks on Hamas targets on Abbas's Fatah party. This time, however, suspicion has fallen on fundamentalist Muslims, or Salafis, whose agenda of global jihad, or holy war, against the West is at odds with Hamas's nationalist goals.

Hamas forces attacked a mosque in Rafah on Aug. 14 [ID:nLF47066] after the leader of a group calling itself Jund Ansar Allah (Warriors of God) declared Islamic rule in the town on the border with Egypt. Up to 28 people, including the leader, were killed. That sparked warnings of a reaction [ID:nLI78639] and speculation that conflict with Salafis could both complicate and foster Hamas's contact with the West [ID:nLH515758].

WHO ARE THESE SALAFIS?

Click here [ID:nLH515758] for details of known groups.

Most share an agenda with al Qaeda and believe Hamas broke with Islam by taking part in the 2006 Palestinian parliamentary election -- an election which it won, sparking international sanctions. Since Hamas [ID:nLF53592] seized control of Gaza in 2007 from secular President Abbas, Salafis have criticised the Islamist movement for failing to implement Islamic law.

Though they may not have a clear hierarchical connection to al Qaeda, they admire its leaders, Osama Ben Laden and Ayman al-Zawahri. Reliable data is scant but various groups may gather hundreds of fighters, including some trained and blooded in the ranks of Hamas but now disillusioned with the ruling movement. For a full study of Salafi groups in Gaza, view this report from the International Peace Research Institute in Oslo here

WHAT MAY BE THE AIM OF THE BOMBINGS?

The attackers hit two heavily guarded Hamas security compounds, one known to include a prison. The second, a residence of President Abbas, is also believed to be used now for detentions and interrogations. If Salafis were behind the bombing, they may be showing both their capabilities and a demand for dozens of imprisoned radicals to be freed.

IS ISRAEL ALSO A TARGET OF RADICALS?

Israel has always been a target for them. The Army of Islam joined Hamas in a border raid in 2006 in which Israeli soldier Gilad Shalit was captured. Shalit is still held and is at the centre of efforts to broker a swap for hundreds of Hamas prisoners. The same group, associated with Gaza's powerful Doghmush clan, has also launched rockets into Israel and fired on troops.

Another group, the Army of the Nation or Jaish al-Ummah, has claimed several rocket attacks against Israel.

Three members of Jund Ansar Allah were killed in an attack in June on an Israeli army position on the border. Some of the attackers rode on horseback.

IS HAMAS AT RISK?

Hamas has thousands of men under arms and easily outnumbers any of these radical groups. Nonetheless, radical ideology and an ability to blend into the population make the Salafis a difficult opponent when they avoid direct confrontation.

Another degree of irritation for Hamas is the Salafis' ability to attack Israel, provoking an Israeli reaction at times when Hamas may be trying to observe a truce.

Hamas officials say they are concentrating on "re-educating" captured radicals, hoping to win them over to a brand of political Islam more in line with Hamas's own principles.

The audience in the Gaza Strip clapped and cheered as the actor delivered the movie's most memorable line – "To kill Israeli soldiers is to worship God".

Imad Aqel, which premiered at the weekend, is the first feature film produced by the Islamist Hamas movement and the title is the name of a Palestinian militant whom Israel held accountable for the deaths of 13 soldiers and settlers.

In accordance with strict Muslim tradition, men and women sat in separate sections of the theatre to view what Hamas officials termed the "Cinema of Resistance", referring to what it describes as a fight against Israeli occupation.

The movie is Hamas's latest foray into the mass media – it owns a satellite TV channel, a radio station and several newspapers.

Imad Aqel was filmed on a set built inside the former Jewish settlement of Ganei Tal in the Hamas-controlled Gaza Strip.

It depicts Hamas's founding in the 1980s, attacks Mr Aqel mounted on the Israeli military in the West Bank and Gaza Strip and the signing of the Oslo peace accord between Israel and the Palestine Liberation Organisation in 1993.

The film cost $120,000 (£70,000) and was written by Mahmoud al-Zahar, a senior leader of Hamas, which the West regards as a terrorist group and shuns because of its refusal to renounce violence, recognise Israel and accept existing interim peace deals.

Mr Aqel was killed at the age of 22 by Israeli soldiers who surrounded his hideout in Gaza in 1993.

Four of the actors in the film, which took several months to make, were later killed in the 22-day offensive Israel launched in the Gaza Strip last December with the declared aim of halting cross-border rocket attacks by Palestinian militants.

Majed Jendeya, the movie's German-trained director, said he hoped to screen the film at the Cannes film festival in France.