Identity papers lie strewn in a pool of blood after a suicide bomber blasted a crowd outside a clinic in Hilla (AP photo)

A suicide car bomber in Iraq has attacked a crowd outside a government building south of Baghdad, killing at least 125 people and wounding 130 others.

The mid-morning bombing in the town of Hilla is the deadliest in Iraq since the fall of Saddam Hussein. Local authorities say they expect the death toll to rise.

Witnesses say the bomber drove a car into a crowd of people seeking medical checkups needed for government jobs. A nearby market place was also destroyed.

Television footage showed survivors collecting scraps of blood-soaked clothing and loading the wounded into fruit carts and trucks.

There has been no claim of responsibility.

In other developments, a special Iraqi tribunal probing criminal charges against the ousted Iraqi leader and his top lieutenants says it is ready to send the first batch of Saddam Hussein's subordinates to trial. No trial date has been set.

The defendants include one of Saddam's half-brothers and a former vice president.