BAGHDAD, Iraq (CNN) -- A female suicide bomber detonated explosives Monday evening in Balad Ruz, killing at least 20 people and wounding 30, according to the Interior Ministry and Col. Ragheb al-Omairi, a Diyala military spokesman.
The bomber struck as Iftar -- the meal that ends Ramadan fasting each day -- was taking place behind the home of a former U.S. detainee. Adnan Shukur had been released from U.S. custody Sunday, and his house lies behind the Balad Ruz police station.
Shukur is a former police official who was detained about a year ago, according to a security official in Diyala province.
Many people, including police officers, were at Shukur's house to congratulate him on his release.
It was not immediately clear if Shukur was among the casualties.
Balad Ruz is 37 miles (60 kilometers) east of Baquba, in Diyala province.
Female suicide bombers have emerged this year as a potent insurgent weapon in Iraq. Insurgent groups have used women as bombers and weapons smugglers because they know women are rarely inspected thoroughly at checkpoints.
One of the tactics the military has used to combat the trend is a program called Daughters of Iraq, a spinoff of Sons of Iraq, which employs Iraqi men to run checkpoints and other security work.
The Daughters of Iraq are being trained to search females at security checkpoints -- something that men are forbidden to do under Iraqi cultural norms.
Last week, coalition forces killed an al Qaeda in Iraq militant who the U.S. military said recruited female suicide bombers in Iraq.