BAGHDAD, (Reuters) – Iraq’s government will confront armed militias and will not allow all-out war as threatened by populist Shi’ite cleric Moqtada al-Sadr, Foreign Minister Hoshiyar Zebari said on Monday.

Zebari’s rebuke of Sadr followed a weekend of fierce fighting in the cleric’s east Baghdad stronghold of Sadr City, described by the U.S. military as the “hottest” in weeks.

In a statement on Saturday, Sadr vowed “open war until liberation” if the government refused to end a crackdown on his Mehdi Army fighters in Baghdad and the southern city of Basra. “Of course nobody will accept open warfare in Iraq or allow the rule of militias to be established,” Zebari told Reuters in Bahrain, where he will attend a regional meeting. “The Iraq government will be very firm to confront all outlaw militias as was proven in Basra and other places.”

Asked if the Iraqi government was capable of confronting Sadr, who led two uprisings against U.S. forces in 2004, Zebari said: “Of course, anybody who challenges the authority of the state, the government has to move.”

Rockets blasted the fortified Green Zone compound in Baghdad on Sunday as U.S. Secretary of State Condoleezza Rice held talks with Iraqi Prime Minister Nuri al-Maliki and voiced support for his militia crackdown and efforts to isolate Sadr.

Clashes between U.S. forces and Shi’ite militiamen in Sadr City killed eight people late on Sunday, the U.S. military said, and fighting was also reported in other areas of the capital.

Lieutenant-Colonel Steven Stover, a U.S. military spokesman, said a U.S. drone aircraft had fired a Hellfire missile at three armed men in Sadr City on Sunday night, killing all of them.

Two other U.S. missiles killed four rocket-wielding men in the slum earlier on Sunday and U.S. troops killed one gunman who attacked their observation post in the tightly packed district of two million people, the U.S. military said.

On Monday morning, U.S. forces killed three people who fired a rocket-propelled grenade at a U.S. patrol in the New Baghdad district, south of Sadr City. “We’re still seeing harassment fire,” said Stover. “Our guys are trying to put up barriers and are getting fired on.”

Sadr’s threat of war raises the stakes in his confrontation with Maliki, who has threatened to ban Sadr’s movement from political life unless he disbands his militia.

Maliki’s crackdown has led over the past month to Iraq’s worst fighting in nearly a year, spreading through the south and Shi’ite parts of Baghdad. Although fighting in the south has mainly died down, the Baghdad clashes have continued unabated.

Apart from the Sadrists themselves, the crackdown has been backed by parties across Iraq’s sectarian and ethnic divide. Rice said this support signalled a “coalescing of a centre in Iraqi politics” that was working together better than ever.

Rice is also in Bahrain on Monday for a meeting that will involve Gulf states, Egypt and Jordan.

On Tuesday, both Rice and Zebari will attend a conference in Kuwait on stabilising Iraq. That meeting, which includes Iraq’s Arab neighbours and major powers, follows similar gatherings held in Turkey and Egypt last year.

The meeting in Kuwait will back Iraq’s drive to disarm militias and call for more diplomatic missions to be opened in Baghdad, according to a draft statement obtained by Reuters.

Washington has long urged Sunni Arab states to beef up embassies in Baghdad to signal support for Maliki’s Shi’ite-led government and to blunt Iran’s influence in the country.