Violence and insurgent attacks have persisted in Baghdad and other Iraqi cities despite a crackdown operation launched by U.S. and Iraqi troops to curb insurgency and sectarian violence in the war-torn country.

On Sunday, the death toll rose to 40 while up to 35 people were wounded when a suicide bomber blew himself up outside the campus of College of Administration and Economy in eastern Baghdad, an Interior Ministry source told Xinhua.

Earlier, the source said that 10 people were killed and 20 others wounded, most of them were students.

Meanwhile, central Baghdad witnessed mortar rounds attack, which wounded three people in the Elwiyah neighborhood.

Earlier in the day, rockets hit the Abu Dshier neighborhood in southern Baghdad, wounding two people.

On Sunday morning, a car bomb blew up some 100 meters away from the Iranian embassy near the Green Zone in central Baghdad, killing two civilians, wounding four others, the police said.

In addition, the death toll rose to 45, with up to 110 people wounded, in Saturday's truck bomb blast near a Sunni mosque in the western Iraqi town of Habbaniyah, local police source said on Sunday.

 
On Saturday, dozens of people were killed despite Prime Minister Nuri al-Maliki announced that U.S. and Iraqi security forces have killed some 400 suspected insurgents since the start of a major crackdown in Baghdad.

"So far, we have 426 suspected militants who had been detained and around that number have been killed during the crackdown," al-Maliki told reporters during a visit to command headquarters for the operation dubbed "Operation Imposing Law."

Nevertheless, eleven days ago, persisted violence was almost routine. But the presence of some 85,000 U.S. and Iraqi security forces spreading out across the capital for the major offensive to curb violence was supposed to make a difference.

A suicide car bomb struck a checkpoint protecting the house of a powerful Shiite leader Abdul Aziz al-Hakim in the Jadriyah neighborhood in southern Baghdad on Saturday, killing one of the guards and wounding four others, police said.

The guards first opened fire on the speeding suspicious car and killed the driver who blew up the car, they said.

The suicide car bombing was the third in the day after a first car bomb detonated near a passing police patrol in the crowded commercial area of the al-Alawi in central Baghdad, killing two people and wounding seven others, the police said.

The second car bomb went off at the al-Jamia district in western Baghdad, killing two people and wounding four others.

Mortar barrage showed up again on Saturday after abating for eleven days of the security plan in the capital, when a rocket and two mortar rounds landed on a residential area in the Shula neighborhood in the afternoon, killing one civilian and wounding 14 others, including three policemen, the police said.

Another mortar barrage hit the Abu Dshier neighborhood in southern Baghdad, wounding 10 people, the source added.

In a separate incident, unknown gunmen in two vehicles stormed a checkpoint manned by Iraqi policemen near the Baghdad airport, killing eight policemen and wounding two, a U.S. military statement said.

To the north, Iraqi forces backed by U.S. aircraft clashed with gunmen early Saturday at a base belongs to the Islamic Army in Iraq, one of the largest Sunni insurgent groups, in the area of Mashahda, 30 km north of the capital, killing dozens and detaining leader of the base Saad Akram Khalifa, an Interior Ministry spokesman said.

On Feb. 14, al-Maliki announced the start of a new security plan in Baghdad and other Iraqi cities.

Under the security plan, Baghdad is divided into 10 districts, jointly patrolled by U.S. troops and forces from Iraqi defense and interior ministries.

Meanwhile, U.S. President George W. Bush has decided to send 21,500 more American troops to Iraq and thousands of them have arrived in Baghdad to support the security plan.

Editor: Yan