US forces and Iraqi militants broke out again fierce clash in the restive Iraqi city of Fallujah late Tuesday, CNN reported.

A US AC-130 gunship was firing on militants positions in the northern part of the Sunni Muslim city after three mortars fell on a US base as a two-week fragile truce appeared to be falling apart, witnesses were quoted as saying.

They added explosions shook Fallujah after dark and large plumes of smoke rose into the air as fighting erupted for the second straight night.

Blasts and gunfire went on steadily for more than half an hour in sustained fighting and flames could be seen rising from building while mosque loudspeakers in other parts of the city were calling on firefighters to mobilize. 

Source: Xinhua