Hundreds of Hamas supporters demanding the execution of an alleged collaborator with Israel have clashed with Palestinian police in the Gaza Strip.

Hospital sources say at least 23 people - three or four with bullet wounds - were injured in the melee outside a police station in the border town of Rafah on Wednesday.

Protesters threw stones and Molotov cocktails at security forces, who fired bullets, mostly in the air.

The demonstrators blame a man, now in Palestinian police custody, for the collaborating in the killing of six Hamas members last week by Israeli forces in a helicopter attack.

Rafah has been seething since Hamas originally kidnapped and interrogated the alleged collaborator several days ago.

The Islamic militant group says there is a video of his confession, and there were plans for a public execution.

But the Palestinian Authority then intervened.

Along with local faction leaders, it convinced Hamas to hand the man over to Palestinian police to prevent a breakdown of law and order.

Frequent targets

Local clan leaders managed to restore calm after the violence.

But Hamas supporters are insisting that the Palestinian Authority carry out the death penalty.

Palestinians have turned on alleged collaborators with fury over the past few months.

Suspected Palestinian collaborators have been frequent targets of unidentified gunmen, who are rarely caught.

Correspondents say Israel has relied on Palestinian collaborators in locating and killing wanted Palestinian militants.