US troops bombarded the besieged city of Fallujah west of Baghdad late Thursday, hours after a US commander announced the planned withdrawal of the Marines surrounding it.

Explosions and gunfire were heard in the northern area, with US warplanes roaring over the city, witnesses said.

It was not immediately unknown if there were any casualties.

American forces have dropped heavy bombs in the last three days, as efforts to negotiate a peace accord was repeatedly disrupted.

The Pentagon insisted that the continuous airstrikes were not intended to end the current ceasefire.

A US commander said earlier on Thursday that the Marines will end the siege of Fallujah and they will start their withdrawal on Friday to allow a newly established Iraqi security forces to move into the city.

The move is according to a new agreement signed by US officials and representatives of Fallujah on Wednesday evening.

The agreement stated the establishment of a new security forces called Fallujah Protective Army (FPA) which will consist of 1100 Iraqi soldiers led by an Iraqi general from the former Iraqi Army, Lieutenant Colonel Brennan Byrne told reporters.

He said the Marine will pull out from their positions in and around the city to pave the way to the FPA to deploy around the city and then to enter it.

"The plan is that the whole of Fallujah will be under the control of the FPA,'' Byrne said.

Fallujah has witnessed bloody clashes between the US forces and insurgents since April 5 following the killing and mutilation of four US civil security in the city.

Source: Xinhua