Three policemen from Palestinian President Mahmoud Abbas's security forces, two Hamas gunmen and a bystander have been killed in exchanges of gunfire in the West Bank.
Palestinian officials say the clashes erupted after the president's Fatah dominated forces raided a neighbourhood in the city of Qalqilya to arrest Hamas gunmen.
Security officials said earlier that a Hamas militant was also killed.
Mr Abbas's forces have imposed a curfew on the city.
