An adviser to Mahmoud Abbas said the Palestinian president sees no need to quit indirect Middle East peace talks over Israel's assault on a Gaza-bound humanitarian aid ship.

The killing of nine pro-Palestinian activists in Monday's Israeli raid has raised concern that US-led efforts to broker an Israeli-Palestinian peace deal could be disrupted.

Mr Abbas met late on Monday with senior PLO officials to assess the situation. His adviser Mohammed Ishtayeh says Mr Abbas told the group there is no need to quit the negotiations since the Palestinians are talking to the US and not to Israel.

Earlier, the UN Security Council held an emergency meeting, with the Palestinians and Arab nations demanding condemnation and an independent investigation.

Riyad Mansour, the Palestinian UN observer, called the attack on unarmed civilians on board foreign ships in international waters a "war crime", and said that "those fleets, one after the other, will be coming until the unethical blockade is put to an end and the suffering stops for our people".

While the Palestinians insisted that those on the ships were humanitarian and human rights activists, Israel's deputy UN ambassador Daniel Carmon said "this flotilla was anything but a humanitarian mission".

Some activists had "terrorist history" and its organisers support radical Islamic networks such as Hamas, which controls Gaza and refuses to recognise Israel's existence, he said.