April 30 (Reuters) - Following are security developments in Iraq at 1200 GMT on Monday:

* denotes new or updated item.

* RAMADI - A tanker laden with chlorine gas exploded near a restaurant west of the Iraqi city of Ramadi, killing up to six people and wounding 10, police and hospital sources said.

* BAGHDAD - Mortar rounds killed one civilian and wounded six when they landed on a residential area of northern Baghdad's mainly Shi'ite district, police said.

* BAGHDAD - A car bomb killed one person and wounded six others when it exploded on a main street in southern Baghdad's Bayaa district, police said.

* YUSUFIYA - Gunmen killed two people, including an Iraqi contractor, when they carried out a drive-by shooting in the town of Yusufiya, just south of Baghdad, police said.

* SUWAYRA - The bodies of six people were retrieved from two rivers in Suwayra, 40 km (25 miles) south of Baghdad, police said.

* BAGHDAD - A roadside bomb killed a person and wounded six others in eastern Baghdad, police said.

* BAGHDAD - The Iraqi army arrested 138 insurgents during the last 24 hours in different parts of Iraq, the Defence Ministry said.

BAGHDAD - At least two people were killed and 15 wounded when a bus bomb exploded in a tunnel targeting a police checkpoint, police said. The explosion badly damaged the tunnel, which is on a main artery in western Baghdad. SAMARRA - U.S. forces detained 11 suspected insurgents during raids in Baghdad and in the city of Samarra targeting al Qaeda in Iraq, the U.S. military said. BAGHDAD - Eight gunmen were killed in a U.S.-Iraqi operation in Baghdad on Sunday, the U.S. military said, in what some witnesses described as a clash with the Mehdi Army militia loyal to Shi'ite cleric Moqtada al-Sadr. The U.S. military said in a statement one Iraqi soldier was killed in the incident in the Shi'ite Kadhimiya district.

BAGHDAD - A roadside bomb killed one civilian and wounding two people in the Bayaa district of southwestern Baghdad, police said. A hospital source said four were killed and nine wounded by the blast.

BAGHDAD - Three U.S. soldiers died and another was wounded when their vehicle was struck by a roadside bomb while conducting a combat patrol in eastern Baghdad on Sunday, the U.S. military said. An Iraqi interpreter was also killed in the attack.

BAGHDAD - A U.S. soldier was killed when a combat patrol was attacked with small arms fire in eastern Baghdad on Saturday, the U.S. military said.

MOSUL - Six gunmen were killed and two wounded when they attacked a police station in the city of Mosul, 390 km (240 miles) north of Baghdad, police said. A car bomb exploded near the police station targeting a patrol heading to the scene of the attack, killing a policeman and wounded two others, the source added.

BASRA - At least five people were killed and 16 wounded by an accidental detonation whilst explosives and weapons were being moved on Sunday night in the city of Basra, 550 km (340 miles) southeast of Baghdad, British forces and Iraqi police said.

BAGHDAD - Gunmen killed three street cleaners on Sunday in the Adhamiya district of northern Baghdad, police said.

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