"The operation, based on reliable intelligence reports, began this afternoon by al-Rasafa security forces in Baghdad," al-Askari told Voices of Iraq.'

The tribal leaders allied with U.S. troops against al-Qaida were kidnapped from their convoy while returning home Sunday from Baghdad.

Elsewhere, A suicide insurgent wearing a bomb-filled vest killed 32 people and wounded more than 20 others Monday in the northeastern Iraqi city of Baquba, officials said.

A police officer in the province of Diyala told the Kuwaiti news agency KUNA by telephone the attacker sneaked into the courtyard of a police station and detonated his bomb in the middle of a group of cadets around 8:15 a.m.

A Washington Post correspondent quoted a police official as saying the death toll could rise.