Youssifiyah is about 20 kilometres south of Baghdad.
Police officials said the attack started late Wednesday and lasted for a few hours. They confirmed the military's account and said the attackers withdrew after the arrival of security enforcements to the area.
Thursday afternoon, a car bomb exploded in a commercial street in Mahmoudiya town just south of Baghdad, killing three people and wounding 12, police said.
Another car bombing in the town of Haswa, 50 kilometres south of Baghdad, killed one person and wounded five, police said.
Medical officials in nearby hospitals confirmed the casualty figures from the car bombings. All officials spoke on condition of anonymity because they were not authorised to speak to journalists.
Violence has escalated in Iraq over the past year. Last year, Iraq saw its highest death toll since the worst of the country's sectarian bloodletting began to subside in 2007, according to United Nations figures.
The country will hold its first parliamentary elections since the withdrawal of US troops on April 30.