Dozens of Palestinian gunmen shot their way into the office of the Palestinian intelligence service early Sunday and burned down the one-story building, witnesses said.

An extreme offshoot of Yasser Arafat's Fatah movement (search) carried out the attack to protest Arafat's appointment of his intelligence chief, Moussa Arafat, to chief of the Palestinian security forces.

The Al Aqsa Martyrs' Brigades (search) says Moussa Arafat, also Yasser Arafat's cousin, is corrupt and is demanding "real" reforms.

The Palestinian leader has overhauled security forces recently -- a key U.S. and Israeli demand for restarting the deadlocked peace process.

The changes follow a sudden wave of kidnappings in the Gaza Strip that signaled a breakdown of authority.

The destruction of the intelligence office on the outskirts of the Khan Younis refugee camp was the latest violence.

Gunmen fired on a group of between seven to nine security guards inside the office. A gunbattle erupted culminating in the destruction of the building when gunmen burned it down.