The Iraqi capital city of Baghdad on Saturday remained under curfew for the second day, as gunmen raided two Shiite homes and killed 21 men in Diyala province.

In spite of the curfew, gunfire crackled throughout the day and an Interior Ministry official told Xinhua that mortar rounds shelled Baghdad's several neighborhoods, including Sadr City, a Shiite militia bastion where more than 200 people were killed on Thursday in the deadliest bombing attacks since the US-led invasion in 2003.

The official said that mortar rounds also hit the Shiite-dominated Harriya district in northern Baghdad, causing no casualty.

On Friday, a Sunni enclave in the district was attacked by suspect Shiite militants. Four Sunni mosques and some houses were burned and dozens were feared dead, seen as a retaliation for the bombings in Sadr City. According to al-Jazeera English service, at least six Sunni Iraqis were burned alive in the attack.

A Sunni resident who identified himself as Ali told Xinhua by telephone that his neighborhood, al-Karradah in southern Baghdad, was relatively calm on Saturday due to the curfew, and more checkpoints manned by Iraqi police and army were set up nearby.

However, Ali feared that the bombings in Sadr City made things worse, and as soon as the curfew was lifted, Shiites would launch massive reprisal attacks, which may push the country into a civil war.

The curfew also forced Iraqi President Jalal Talabani to delay a trip to Tehran.

The president said on Friday that he has postponed the visit due to airport closure under curfew in Baghdad, but "as soon as the airport opens we will leave for Tehran."

In Diyala province, seen as a stronghold of Sunni insurgents, gunmen raided two Shiite homes and killed 21 men in execution style on Friday night, police said on Saturday.

Police said that suspect insurgents in five cars dragged 21 men from two families in a Shiite village, 75 km northeast of Baghdad, and executed all of them. The corpses were taken to a morgue Saturday morning.

In Baquba, capital of Diyala, more than 30 insurgents were killed by US and Iraqi forces on Saturday, police said.

Meanwhile, US forces killed 22 insurgents and an Iraqi civilian and destroyed a factory used to make roadside bombs in several operations north of Baghdad on Saturday, the military said in a statement.

The military also said that US troops killed 12 insurgents on Saturday morning in an operation to capture a militant "associated with the manufacturing of vehicle bombs and facilitating foreign fighters into northern Baghdad area."

(Xinhua News Agency November 27, 2006)