British forces turned over responsibility for Basra to the Iraqis in late December but say they will assist the Iraqis upon request.
Followers of al-Sadr also have been fighting US and Iraqi forces in Baghdad and other cities in reaction to the Basra crackdown. Fifteen people were killed and 100 wounded in clashes in Sadr City that broke out Tuesday, according to police and hospital officials, who spoke on condition of anonymity because they weren't authorized to release the information.
Hundreds of Sadr City residents took to the streets on Wednesday, demanding the government stop military operations in Basra and other cities and withdraw all security forces.
"We strongly condemn the assaults being conducted by the occupation forces along with the Iraqi security forces who have sold themselves to the renegade occupier," said demonstration leader Sheik Saleh al-Eraibi.
Nobody claimed responsibility for the attacks against the Green Zone, which houses the American and British embassies as well as the Iraqi government headquarters.
The US military blamed Iranian-backed Shiite militia factions for a spate of rockets that struck the sprawling area on Sunday, killing an American financial analyst working for the embassy. Another volley slammed into the area on Tuesday, but Nantongo said no deaths or major casualties were reported.
A mortar shell or rocket that apparently fell short on Wednesday also struck a minibus in the mainly Shiite district of Karradah, killing at least two passengers and wounding seven others, according to police and hospital officials.
Two other Iraqis were killed and four wounded when another round struck a residential area in a Shiite neighborhood in western Baghdad, police said.