Iraq's radical cleric Moqtada al-Sadr ordered his followers to reject Prime Minister Nuri al-Maliki's call to surrender their arms as clashes with troops raged for a fifth straight day.
Since Tuesday violence has raged across Shia regions of Iraq, with nearly 230 people killed as Shia fighters clashed with government troops.
On Wednesday, Mr Maliki gave a 72-hour deadline to Shia fighters to give up their guns in the southern city of Basra after launching a crackdown against them on Tuesday.
The death toll from clashes between Shia gunmen and Iraqi and US troops in Baghdad's Sadr City rose to at least 75, with another 498 people reported wounded.
In Basra eight people were killed in a new air strike this morning as clashes continued there for the fifth straight day.
The countrywide death toll from the firefights has surged to nearly 230 since Tuesday.
Most of the casualties are in Sadr City, Basra, the southern city of Nasiriyah and the central cities of Kut and Hilla.
US President George W. Bush called the current clashes a ‘defining moment’ for Iraq and a key test for the country's government.
In Baghdad most main roads are deserted as the city remains under curfew for the second day.
The Green Zone, seat of the government and the US embassy, again came under rocket attack this morning but it is not known if there are any casualties.
