More than two thousand demonstrators gathered in the West Bank town of Ramallah to call for the execution of Palestinian policemen who they say killed a teenager in Ramallah on Sunday.

Wasim Youssef al-Tarifi was shot dead while taking part in a protest by supporters of Yasser Arafat's Fatah movement over a police raid on Fatah offices.

Palestinian security officials say it's unclear who fired the shots.

The governor of Ramallah, Mustafa Isa, has set up a committee to look into the incident.

The Palestinian authorities say they've arrested the policemen who raided the Fatah offices, allegedly to seize illegal weapons.