BAGHDAD, Iraq (CNN) -- A top official in Baghdad said the capital's biggest stadium is one of three locations being prepared for residents fleeing Baghdad's Sadr City, where Iraqi and U.S. forces have been fighting Shiite militants for weeks.
An Iraqi mother and daughter walk near a checkpoint at the entrance to Baghdad's Sadr City on Wednesday.
Tahseen al-Sheikhly, the civilian spokesman for the Baghdad security plan, said no more than 400 families have fled the war-torn neighborhood so far. There have been reports that thousands of people have fled.
Al-Sheikhly discounted reports that soldiers have been using loudspeakers to tell people to leave. He said "criminal gangs" are spreading the rumor to generate fears among the populace that a big strike is being prepared by security forces. He said gangs are trying to generate hatred of security forces by distributing a "fabricated" video of coalition forces assaulting a woman.
Those families that are leaving, he said, are residents who have been cooperating with security forces, families of security forces who have been threatened, and people who have been "held hostage by the criminal gangs."
He said one man left after he protested to insurgents that they were planting a roadside bomb too close to his house and the insurgents told him to leave the area.
U.S. and Iraqi troops have been battling Shiite militants in the district since late March. Casualties are believed to be around 1,000 militants and civilians dead and more than 2,000 wounded in the district.
American and Iraqi officials have reported clashes from Wednesday afternoon to Thursday morning in and near the sprawling, predominantly Shiite slum in northeast Baghdad, the home of 2.5 to 3 million people.
The American military said battles between soldiers and militants in Sadr City and in nearby Shiite enclaves left around a dozen fighters dead. Iraq's Interior Ministry said four people were killed and 12 people wounded in clashes between "outlaws and U.S. soldiers" in Sadr City. Hospital officials in Sadr City reported at least five deaths and 26 injuries.
Claire Hajaj, a UNICEF spokeswoman, said up to 150,000 people, including 75,000 children, had been isolated in parts of southern and eastern Sadr City under heavy military control. Fighting has moved slightly north and east and displacement is expected in those areas as well, she said.
In areas where fighting has raged, there have been disruptions to food supplies and access to health care services. She said schools have been closed and the impact of that educational disruption is expected to continue after the crisis ends.
It is possible that as many as 1,000 families could be displaced, Hajaj said, but it is hard to get a handle on displacement figures. She said many people are thought to be looking for or already living in temporary shelters, with many of them hoping to go back home as soon as possible. People are taking refuge in mosques, schools and friends' homes, she said.
Meanwhile, in northern Iraq, a former al Qaeda in Iraq local leader who now works for an American-backed security group was wounded in a suicide bombing on Thursday, police said.
The suicide bomber, wearing an explosive vest, attacked a convoy in the Salaheddin province town of Dhuluiya, wounding five people.
They include Awakening Council leader Sheikh Nadhem al-Jabouri, who was formerly an al Qaeda in Iraq leader in Dhuluiya, and Dhuluiya Police Chief Mohammed Khalid.
Al-Jabouri left al Qaeda in Iraq a year ago and formed the Awakening Council. He has been meeting regularly with U.S. military officials and the town's police chief to update them on security in the area.
Sunni militants -- such as those in the al Qaeda in Iraq movement -- long have targeted Iraqi security forces and Sunnis aligned with groups that help U.S. and Iraqi forces with security. The groups are called Awakening Councils and Sons of Iraq.
On Wednesday, a Sons of Iraq group in Salaheddin province killed four people described as "insurgents" after repelling an attack, the U.S. military said. The group found suicide vests, 800 pounds of homemade explosives and other material for producing bombs, the military said.
"Any effort in which forces can eliminate excessive amounts of explosives, places Iraq one step closer toward a state of overall security," said Maj. Peggy Kageleiry, spokesperson for Multi-National Division-North.
Also Thursday, at least seven people were killed and 19 wounded when a parked car bomb detonated in the parking lot of a restaurant in western Baghdad. Three police officers were among those killed and two were among those wounded in the strike, which apparently targeted police. Two women and a child were wounded. Cars and shops were damaged as well.
At least six people were killed and 18 others wounded in other attacks in Baghdad Thursday afternoon. One strike killed three civilians, another caused Iraqi military casualties, and a third killed a bus passenger.
Three civilians were wounded in a bombing behind central Baghdad's National Theatre. On Sunday a roadside bomb near the theatre struck the motorcade of Iraq's first lady, Hiro Ibrahim Ahmed, the wife of President Jalal Talabani. She escaped unharmed.
CNN's Jomana Karadsheh, Mohammed Tawfeeq, Yousif Bassil and Joe Sterling contributed to this report.