Synchronized car bombs devastated a city market district in southern Iraq on Wednesday, killing at least 27 people and injuring 151 in a Shi'ite region that has largely escaped the country's sectarian bloodshed, authorities said. The police chief in Amarah was fired, an immediate driving ban went into effect, and Iraqi soldiers deployed on the streets. In a Christian neighborhood in eastern Baghdad, a parked car bomb apparently targeting a police patrol killed five civilians, police said. Thirteen people were wounded in the late afternoon explosion in Ghadeer, police said. The blasts in Amarah came about five minutes apart, beginning about 10 a.m., when an explosives-laden car parked in a garage blew up, police and an intelligence official said. Another car about 50 yards away exploded shortly afterward as people gathered to examine the damage from the first blast, police said. The police and intelligence officials spoke on condition of anonymity because they were not authorized to release details of the attack. The explosions could be felt a half-mile away, said Salam Hussein Jabr, who runs a travel agency. He said his office windows shook and two pictures fell off the walls, and he ran outside to see what had happened. "This is the first time we've gone through anything like this," said Jabr, a 44-year-old father of three. Initially, Jabr said, people thought it was a mortar attack. Then the second car exploded. "Police prevented us from getting near. I saw about 100 people on the ground and police, soldiers and civilians were evacuating them," he told The Associated Press by telephone. Black smoke billowed over the skyline and flames shot out of cars. Rescue crews worked to evacuate the victims. Sandals apparently lost in the rush lay near pools of blood. Mohammed Sabri, an elementary school principal, called for more security in the city. "Amarah is a quiet and stable city, but it seems that terrorists have arrived here," he told AP Television News. In Baghdad, Maj. Gen. Abdul-Karim Khalaf, the Interior Ministry spokesman, said 27 people were killed and 151 wounded in the twin explosions. He said the police chief was fired. There were conflicting accounts of the number of bombings, with some officials saying two cars had exploded and others saying a third bomb exploded outside a movie theater. Mohammed Saleh, a provincial council spokesman, said police detained 25 suspects, including some who were using cell phones and cameras nearby, and were questioning witnesses. He said an indefinite driving ban was imposed, and Iraqi soldiers were deployed on the street. "We are focusing on evacuating casualties to the hospital," Saleh said. No one claimed responsibility for the attack. Amarah, a Shiite militia stronghold about 200 miles southeast of Baghdad, has seen violence among rival groups vying for control in Iraq's oil-rich Shi'ite southern heartland, which has no significant Sunni population. Al-Qaida is not known to have a significant presence in the region, although the terror group is often blamed for spectacular car bombings elsewhere in Iraq. The city is the provincial capital of Maysan province, which borders Iran. Iraqi forces took over control of security from British troops there in April. The British are expected to turn over neighboring Basra province, the last area under their control, in mid-December. Prime Minister Nouri al-Maliki, who was visiting Basra on Tuesday, said the attack was a "desperate attempt" to undermine efforts to stabilize the country. "Any criminal act they commit would only be a desperate attempt to draw attention away from the clear successes and to break through the siege imposed on the defeated groups," he added. He also called on residents in Amarah to exercise restraint and avoid revenge attacks against the "terrorists who do not want Iraq to stand up again." Philip Reeker, a US Embassy spokesman, said recent attacks highlighted the dangers still facing Iraq, even as violence has declined in Baghdad and elsewhere in the country. "We are by no means declaring a victory against those who would like to disrupt the progress in Iraq," Reeker said at a news conference. "We've seen that today, we've seen that yesterday with bombings, just as we've seen bombings around the world."