Palestinian officials accused Israel of escalating tensions already running high over moves which Palestinians say aim to deepen Israeli control over the territory.

Palestinian government spokesman Ghassan Khatib called for an independent investigation into the killing of cousins Mohammed Qawariq and Saleh Qawariq on Sunday, citing witness accounts they had been shot only after being arrested.

Mahmoud Al-Aloul, a senior figure in Fatah, said they had been killed in "cold blood": "Nobody can imagine that we can stand with our hands tied vis-à-vis what is happening," Aloul told around 1,500 mourners at their funeral in Awarta, south of Nablus.

One of the bodies was wrapped in a yellow Fatah flag and the other in the green flag of Hamas. A few kilometers from Awarta, the two teens killed by Israeli forces on Saturday were also buried in the village of Iraq Burin. Palestinian medics said Mohammed Qadus, 16, and Osaid Qadus, 17, were killed by gunfire during clashes with Israeli forces. The medics showed reporters evidence of live bullets being used by troops on protesters although Israeli forces said only rubber bullets were used.

Abbas spokesman Nabil Abu Rudainah said Israel had responded to international efforts to revive peace talks with violence.

Meanwhile, Israeli Prime Minister Benjamin Netanyahu said Sunday he had told Washington in writing, just before heading for talks with US President Barack Obama, that Israel would not stop Jewish settlement around Jerusalem. The settlement issue is challenging renewed efforts by US envoy George Mitchell to get peace talks under way.