A car bomb has killed at least 55 people and injured about 70 in the Iraqi city of Karbala, in the second such attack in two weeks.

The city houses two of Shia Islam's holiest shrines and reports say the bomb went off on a busy street as people headed to pray.

The bomb exploded near the golden-domed mosque of the Imam Abbas shrine, which is protected by a barrier.

A suicide bomber killed at least 42 people in Karbala on 14 April.

Karbala is the second most important shrine city for the Shia, the BBC's Andrew North reports from Baghdad.

He notes that attacks on shrines have become a hallmark of al-Qaeda.

Crowd fury

Iraqi television images from Karbala showed a man running down a smoke-filled street holding a lifeless baby above his head.

Ambulances had rushed to the scene, in a crowded area full of shops and restaurants in the city, 100km (70 miles) south-west of the Iraqi capital, Baghdad.

Angry people gathered at the blast site, many of them searching frantically for missing relatives, The Associated Press reports.

Some began to throw stones at the police, accusing them of failing to protect the people.

Police fired weapons in the air to disperse the crowds, the agency says.

Earlier, the powerful Shia cleric, Moqtada al-Sadr, criticized US President George W Bush for refusing to establish a timetable for a US troop withdrawal from Iraq.

In a statement read out on his behalf in the Iraqi parliament, the cleric said the situation in Iraq could not be any worse following an American pull-out than it was already.

Photo caption

A man is comforted at the scene of the 28 April Karbalaa bombing