BAGHDAD, Iraq - Police and medical workers said at least 20 Iraqis were killed in clashes Tuesday in Ramadi, where US ground troops and warplanes have conducted a series of operations over recent days targeting Sunni insurgents.

Iraqis inspect remains of a minibus destroyed in an explosion in Baghdad, Iraq, Monday, Nov. 13, 2006. Violence rattled the center of Iraq on Monday when a bomb exploded in a minibus in Baghdad's largely Shiite Shaab neighborhood, killing at least 20 people and wounding 18. Elsewhere at least 10 other Iraqis died violently, including a member of the Diyala city council. [AP]

Ali al-Obaidi, a medic at Ramadi Hospital, said those killed were civilians who died in shelling by US tanks. A police spokesman said 20 people were killed, but gave no information about their identities or how they died.

The US military said it had no information on fresh Ramadi clashes.

Insurgents have grown increasingly bold around Ramadi, which lies deep in the Sunni heartland west of Baghdad where tribal leaders were strong allies of deposed Saddam Hussein.

US forces said they used air-launched weapons on Saturday to destroy a building in the city that had been booby-trapped to explode upon entry. The military said there were no reports of civilian casualties in that attack.

In other violence, assailants killed seven passengers aboard a minivan ambushed Tuesday near Mandali on the Iranian border, Diyala provincial police said.

Special coverage: Iraq After War

Six people were killed in fighting overnight between Shi'ite gunmen and American forces in Shula, northwest Baghdad, police spokesman Mohammed Kheyoun said. Residents said US warplanes had fired rockets at homes in the area and put the death toll as high as nine. The US military has not commented on the reports.

Elsewhere in the capital, one person was killed when a car bomb detonated near a restaurant in west Baghdad, police Lt. Maitham Abdul-Razzaq said.

Three insurgents were blown apart trying to plant a roadside bomb Monday night in the northwestern city of Mosul, police Brig. Abdul-Karim Ahmed Khalaf said.

The US military, meanwhile, said an airstrike killed three insurgents suspected of being part of a bomb-making ring in Youssifiyah, 12 miles south of Baghdad.