U.S. military police shot and killed two detainees and wounded five others in an effort to put down a massive brawl that broke out Wednesday at the notorious Abu Ghraib (search) prison facility west of the Iraqi capital.

Troubles began when several detainees attacked another inmate with rocks and tent poles in a fight that quickly escalated, drawing in 200 inmates at a tented detention camp within the sprawling prison compound, said Lt. Col. Barry Johnson, the U.S. military's spokesman for detention operations in Iraq (search).

Detainees hurled rocks at U.S. soldiers, ignoring "verbal warnings" and then a volley of rubber bullets from U.S. military police, Johnson said.

The military decided to use lethal force because one detainee was at risk of being killed by fellow inmates, he said.

"A determination was made that if lethal force wasn't used, this detainee was going to be killed," Johnson said. "So lethal force was used in the form of aimed shots against those most involved in the direct violence against the individual who was being attacked."

One of the detainees was killed on the spot and a second, critically wounded, died of his wounds at a military hospital.

It was not known what caused the fight.

Abu Ghraib was at the center of a scandal over allegations that American prison guards abused Iraqi detainees. The scandal broke in April when photographs of hooded and naked prisoners were made public, unleashing a torrent of international criticism.

U.S. authorities have released thousands of detainees from Abu Ghraib in the last several months.