Efrat, West Bank - Jewish settlers set up 13 makeshift outposts in the occupied West Bank on Tuesday in a show of strength ahead of Israeli elections that could swing on the growing debate over the territory.

Prime Minister Ariel Sharon has vowed to keep major West Bank settlements but has said that some isolated communities may one day have to be dismantled as a way of ending decades of conflict with the Palestinians.

Jewish ultranationalists, furious at Sharon for pulling troops and settlers from the Gaza Strip this year, stake a biblical claim to the land Israel captured in the 1967 war. Palestinians want all of the West Bank and Gaza for a state.

On a hilltop south of Jerusalem, young settlers in knitted skullcaps hammered up wooden frames for buildings.

"The land of Israel belongs to the people of Israel and we are not going to give it up," said Yehuda Matar, 17, from the Efrat settlement, its red roofs visible in the distance.

An Israeli military source said the army was treating the action as a protest of tent encampments and that the settlers had said they would eventually leave, but would be evacuated if they did not.

Nabil Abu Rdainah, a spokesman for Palestinian President Mahmoud Abbas, urged Israel "to cease these activities and uproot the outposts".

Israel is meant to remove dozens of West Bank outposts not authorised by its government under the U.S.-led "road map" for Palestinian statehood, but almost all remain.

Israel has also failed to stop building inside established settlements, all branded illegal by the World Court. Israel disputes this. New building tenders were announced on Monday for 228 West Bank settlement homes.

Palestinians have failed to meet their own road map pledge to start disarming militants.

The fate of the West Bank is one of the key issues ahead of March 28 elections in which Sharon is campaigning for a third term on a centrist platform after quitting the rightist Likud, many of whose members oppose withdrawing from any land.

Lagging in the polls, Likud is trying to claw back ground from Sharon, whose withdrawal from Gaza was widely popular.

Likud points to continuing rocket fire by Palestinian militants in Gaza to bolster its argument that leaving territory does not bring peace.

Israeli warplanes struck Gaza on Tuesday after Sharon gave a go-ahead for the imposition of a no-go zone within the territory to try to stop the rocket attacks. Palestinians call the buffer zone plan tantamount to re-occupying the strip.

Palestinians are struggling with their own internal problems ahead of a parliamentary election next month in which President Abbas's Fatah faces a strong challenge from Hamas militants, who oppose talks and want to destroy Israel.

In a sign of growing unrest, gunmen from a Fatah faction briefly seized three buildings in the Gaza Strip and an election office in the West Bank on Tuesday.

But Palestinian officials said Abbas was close to coming up with a single Fatah election list that could be presented on Wednesday, healing a damaging split between a corruption-tainted old guard and younger leaders seeking a bigger share of power.

Some 245,000 settlers live among 2.4 million Palestinians in the West Bank. About 200,000 Israelis also live in Arab East Jerusalem, which Israel also captured in 1967 and annexed in a move not recognised internationally.