Thousands of Palestinians congregated in the West Bank town of Nablus on Wednesday in a strong show of support for President Mahmoud Abbas ahead of reconciliation talks between rival Palestinian factions set to begin in Cairo.

Later in the day, representatives of Abbas' Fatah movement are to sit down in Egypt with envoys from the Islamic militant group Hamas to try to plaster over the gaping political rift that divides them.

Fatah on Tuesday released some 42 Hamas prisoners as a goodwill gesture ahead of the reconciliation talks.

Maher Halaby, the Fatah chief in Nablus, said tens of thousands of people from across the West Bank had arrived in the city by midday. Many in the crowd opposite An-Najah University were carrying yellow Fatah flags and red, white, green and black Palestinian flags.

The two movements have been bitter rivals for years. The rift came to a head in June 2007 when Hamas violently seized control of Gaza after days of street fights with Fatah.

Since then, Abbas has controlled only the West Bank and Hamas has ruled Gaza.

Earlier attempts at reconciliation have failed. But after Israel's blistering assault on Gaza last month, the factions have a greater stake in putting aside their differences.

Gaza desperately needs foreign aid to rebuild after the war, and Hamas knows the impoverished territory will remain internationally isolated unless the Western-backed Abbas is given a toehold there.

Abbas needs Hamas to help shore up his standing after his term as president expired last month, and after a victory by hard-liners in Israel's recent election undercut his hypothesis that peaceful negotiations with Israel will produce a Palestinian state.