A series of coordinated bombings killed 153 people in a Shiite militia stronghold in eastern Baghdad on Thursday, prompting the authorities to impose an indefinite curfew.

A further 201 people were also injured when four car bombs in short succession struck 55th Square, al-Sadrain Square, the popular Hai market and Mudhafar Square in Sadr City on Thursday afternoon, a well-informed Interior Ministry official told Xinhua.

The anonymous official denied the earlier report that Mudhafar Square was hit by a mortar round.

There are additional two car bombings near the Shiite district,causing no casualties, the official added.

Shortly after the bloodbath, some 13 mortar rounds shelled a Sunni district in northern Baghdad in retaliation, leaving at least 10 people wounded.

Sadr City in eastern Baghdad is a stronghold for thousands of followers of radical Shiite cleric Muqtada al-Sadr. The revered cleric's militia Mahdi Army is often accused of getting involved in the sectarian violence, in which thousands of people have been kidnapped and tortured and their bodies dumped.

Angry residents and armed militiamen flooded the streets to protest the bloody attacks, denouncing Sunni militants behind it. Some people warned the latest carnage was likely to inflame sectarian passions and pushed the country closed to a full-scale civil war.

The Interior Ministry has imposed an indefinite curfew on Baghdad, Iraqi state-run television reported.

The Iraqiya channel quoted an Interior Ministry official as saying that the curfew began at 8:00 p.m. (1700 GMT) Thursday and all people and vehicles must stay off the streets of the city until further notice.

In other violence, gunmen attacked a Shiite ministry in central Baghdad, prompting fierce clashes with security guards.

"Up to 30 gunmen attacked the Health Ministry in Bab al-Mu' adham area at about 2:30 p.m. (1130 GMT), prompting fierce clashes with Iraqi army and police forces," an Interior Ministry source told Xinhua.

"There is no immediate police report on casualties," the source said, adding that there were some people being taken to nearby hospitals.

Deputy Minister Hakim al-Zamily told the Iraqi state-run television Iraqiya that since Thursday morning the ministry building has been shelled by mortar rounds and machine-gun fire.

Recently, the Iraqi Health Ministry controlled by al-Sadr are frequently targeted. Zamily himself survived assassination attempt on Monday when gunmen attacked his convoy in Bab al-Mu'adham area, killing two of his bodyguards.

A day before that, Ammar Assafar, another ministry deputy was kidnapped when gunmen wearing police uniforms stormed his house in Baghdad's northern district of Adhamiyah.

Earlier this month, militants in police uniforms stormed a building of the Iraqi High Education Ministry in central Baghdad, kidnapping about 100 people, some of whom were released later.

Editor: Donald