BAGHDAD, Iraq – A massive bomb tore through a crowd gathered near a bus station in a Shiite neighbourhood of Baghdad on Saturday, killing at least 22 people and wounding 54, security officials said.

"The toll in the Kadhimiyah explosion has risen to 22 killed and 54 injured," army spokesman Major General Qassim Atta told Agence France-Presse.

He said the explosion occurred in a car park used by commuters near a key city bus terminal in the Shiite neighbourhood of Kadhimiyah, northwest Baghdad.

Initial Iraqi military reports said the source of the explosion was a car bomb. However, a statement from the US military identified the bomb as a homemade bomb and said 18 Iraqi civilians had been killed with 25 wounded.

Discrepancies in death tolls and the type of device used are common in Iraq.

An AFP photographer at the scene said the charred remains of one vehicle pointed to a car bomb. The force of the explosion was so powerful that body parts were scattered across houses and vehicles surrounding the site.

The blast, which occurred around midday (0900 GMT), echoed for kilometres (miles) across the embattled Iraqi capital.

Kadhimiyah, location of an important shrine where two respected Shiite imams are buried, has suffered routine attacks since the 2003 US-led invasion triggered vicious Sunni and Shiite sectarianism.

The level of violence in Baghdad has dropped in recent months but insurgents still seem able to strike at will despite the tight security measures in capital of seven million people.

Saturday's bombing was the deadliest in Baghdad since November 10, when at least 28 people were killed, including women and schoolgirls, and dozens wounded in a triple bombing in a market.

The attackers in November detonated a car bomb in the Sunni district of Adhamiyah, then minutes later a suicide bomber ran into the resulting melee and blew himself up.

On Thursday, one Iraqi was killed and 14 others injured, including three policemen, in a bombing attack in Kadhimiyah, scene of some of deadliest killings in the capital since the invasion.

In August 2005, during a festival attended by tens of thousands of pilgrims marking the death of revered Shiite Imam Musa Kadhim 12 centuries ago, almost 1,000 pilgrims died as a result of a stampede.

A mortar attack and rumors of a suicide bomber among the crowd sparked the tragedy, making it the deadliest incident to hit Iraq in the aftermath of 2003.

In mid-September 2005, at least 128 people were killed by a suicide bomber targeting labourers in Kadhimiyah.