A suicide bomber has killed at least 50 people and wounded 100 others in an attack on police recruits in the northern Iraqi city of Irbil. The militant group Ansar al-Sunnah claimed responsibility on its website for Wednesday's blast, saying it was in retaliation for Kurdish cooperation with U.S. and coalition forces. Another car bomb attack killed nine Iraqi troops in Baghdad Wednesday. More than 200 people have died in insurgent attacks over the last week. Rebels increased attacks after Prime Minister Ibrahim al-Jaafari announced a partial cabinet last week. Meanwhile, the U.S. military says it found the body of a second American pilot missing since two jets disappeared over Iraq this week. Authorities are still trying to determine what caused the jets to crash.