43 killed in police camp bombing.
The two men were wearing explosives-laden vests and a US contractor was among those wounded.
'One of the suicide bombers detonated near a group of students outside a classroom,' a statement said.
'Thinking the explosion was an indirect-fire attack, (Iraqi police) and students fled to a bunker for shelter where the second bomber detonated his vest.'
Five female police officers were among the dead, Iraqi police said.
Iraqi insurgents have concentrated their attacks against Iraqi security forces. The attack was the deadliest against Iraqi forces since February 28, when a suicide car bomber attacked mostly Shiite police and National Guard recruits in Hillah, killing 125.
Meanwhile al-Jazeera television broadcast an Iraqi insurgent video that purported to show a kidnapped US security consultant.
The video showed a blond, Western-looking man sitting down with his hands tied behind his back. The video also bore the logo of the Islamic Army in Iraq and showed a US passport and an identification card.
If true, the man would become the second American taken hostage in the last two weeks. A US citizen was among four peace activists, including Briton Norman Kember, taken hostage on November 27 by a group calling itself the Swords of Righteousness. Two Canadians were also part of that group.