Authorities locked down access to the southern city of Karbala on Wednesday after fierce clashes between rival Shiite militias claimed more than 50 lives and forced an end to a massive religious festival. Security was heightened in other Shia areas to prevent clashes from spreading.
Elsewhere, an American soldier died from wounds suffered on Tuesday in fighting near the northern city of Kirkuk, the US military announced.
Following two days of clashes, Prime Minister Nouri al-Maliki, a Shia, rushed to Karbala to meet with local officials trying to restore order and move the hordes of pilgrims who had descended on the city for the festival.
The Karbala office of al-Maliki's Dawa Party was firebombed during the melee.
Sporadic gunbattles raged on Wednesday near two shrines protected by the Badr Brigade, the armed wing of the Supreme Islamic Iraqi Council, although violence was tapering off.
Clashes began late Monday but escalated dramatically the following day when gunmen believed from the Mahdi Army militia of radical cleric Muqtada al-Sadr began firing on security forces and the Badr guards, according to security officials. But a spokesman for al-Sadr, Ahmed al-Shaibani, denied that the Mahdi Army was involved in the Karbala fighting. Al-Sadr called for an independent inquiry into the clashes and urged his supporters to cooperate with the authorities "to calm the situation down," al-Shaibani said.
Tensions have been rising in southern Iraq as rival Shia groups maneuver for power, especially in the oil-rich area around Basra, Iraq's second-largest city.
The fighting forced authorities to cut short the annual Shabaniya festival, which drew an estimated 1 million people from across the Shia world.
Despite an order to clear the city center, an al-Arabiya television correspondent on the scene reported there remained an "intensive deployment" of Mahdi Army men, waving guns in the air. A Sadrist lawmaker, Hamed Kanoush, was detained by Iraqi security forces and members of al-Sadr's movement threatened to attack the governor's office if he was not released, according to a member of the Karbala Provincial Council, speaking on condition of anonymity out of security concerns.
The fighting claimed at least 52 killed and 300 others injured, according to the director general of the health department in nearby Najaf who spoke on condition of anonymity. Sixty wounded people were brought to a hospital in Najaf, 70 kilometres southeast of Karbala, because the hospitals in Karbala were unable to handle the volume of injuries, he said.
A city council member in Karbala, however, reported 38 dead and 231 injured in the fighting.
The defense ministry announced that al-Maliki had ordered the dismissal of the top army commander in the area Maj Gen Salih Khazaal al-Maliki and an investigation into his conduct. The prime minister's office said security forces had sealed the city off, allowing only residents to enter, in another effort to restore order.
The clashes appeared to be part of a power struggle among Shiite groups in the sect's southern Iraqi heartland, which includes the bulk of the country's vast oil wealth.