At least six Palestinians were killed early Sunday in fierce clashes between Palestinian National Authority (PNA) security forces and armed men from Islamic Resistance Movement (Hamas) in the West Bank city of Qalqilya, witnesses and sources said.

The witnesses told Xinhua that three security men loyal to PNA president Mahmoud Abbas, two Hamas militants and the owner of the building where the Hamas gunmen returned to, were killed in the clashes.

Security sources said that the troubles started shortly before midnight when two gunmen fired at Palestinian forces, escaped to a building and refused to surrender.

A joint force from pro-Abbas apparatuses was called and the armed clashes lasted until dawn. The PNA's troops entered the building in the morning hours after it made sure the militants were killed.

Earlier, Hamas' al-Aqsa satellite channel, based in Gaza, reported that the Palestinian forces were trying to arrest two members of the movement's military wing in the West Bank and called on the Palestinian people to take to the streets in protests.

Sunday incidents were the first violent clashes between Hamas and pro-Abbas forces in the West Bank since Hamas took over control of the Gaza Strip in 2007.

Abbas and his Fatah movement consolidated their rule in the West Bank after they lost Gaza in the deadly fighting. Hamas holds sway in the coastal Strip and Fatah accuses it of cracking down against Fatah supporters and members.