US troops continued military operations on Saturday in western Iraqi cities to crack down on insurgency.

Clashes broke out between US troops and fighters in Iraq's western city of Haditha, some 250km northwest of Baghdad, as the US forces searched for insurgents, witnesses told Xinhua.

The US forces also surrounded the nearby town of Barwana, and US planes airdropped leaflets, threatening the residents with assault if they don't hand over insurgents, according to the witnesses.

Haditha is part of an insurgency-ridden area called the Sunni Triangle including Ramadi and Fallujah in Iraq's Anbar province, where urban life has been paralyzed due to the hard-core military operations.

In Fallujah, some 50 km west of Baghdad, a tribal leader called for protest at the provocative acts of the Iraqi national guards against the residents.

Four national guards were killed in recent clashes with the residents who claimed to be treated brutally.

Tens of thousands of Fallujah residents returned to the city which was almost destroyed by the US major offensive last November.

Source: Xinhua