Insurgents killed four Iraqi people accused of cooperating with the US forces, witnesses told Xinhua onSunday.

Their corpses were found on the sidewalk in a main street in Ramadi, 110 km west of Baghdad.

A paper attached to one of the bodies said the dead were "traitors who cooperate with the occupation forces," adding that "they were killed after they admitted it is just to execute them as an example for other collaborators."

In another incident, the US forces arrested the editor in chief of a local independent newspaper along with his brother.

Ahmed Al Rashid, chief of the al-Jazeera newspaper, was detainedin a raid after a roadside bomb exploded near his house as a US convoy was passing by.

Ramadi is the capital of al-Anbar province, a vast Iraqi governorate where US troops and Iraqi national guards and police aswell as those accused of working with them were most frequently targeted by insurgents.