Updated

The Pentagon (search) has begun criminal investigations of at least 37 deaths involving detainees held by U.S. forces in Iraq and Afghanistan, officials said Friday. There are 33 cases involved, the officials said, eight more than the military reported two weeks ago.

The officials said they could not immediately say for sure the exact number of deaths involved.

Eight pending cases have been classified as homicides involving suspected assaults of detainees before or during interrogation sessions, a senior military official said, speaking on condition of anonymity.

Of the total number of cases, 30 were inside U.S.-run detention facilities and three were outside. Fifteen of the 30 cases were declared by U.S. authorities to be deaths by natural cause or of undetermined cause, the senior official said.

Of the 15 other cases that happened inside detention facilities, four were categorized as justifiable homicides, two as homicides, and nine were still under active investigation, the official said. Eight of those nine have been classified as homicides (search) involving suspected assaults on detainees before or during questioning.

Six of the nine unresolved cases happened in Iraq — including two at Abu Ghraib prison (search) — and three were in Afghanistan.

The 33 total cases date from December 2002 to the present.

Bryan Whitman, a Pentagon spokesman, said members of Congress were briefed on the 33 cases Friday.

In addition to the 30 cases involving deaths inside U.S.-run detention facilities, there were three cases involving detainees who were outside. One was a death involving a soldier who shot and killed an Afghani who had lunged toward a weapon, the senior military officer said.

Another was an Iraqi who drowned after he was forced off a bridge by a U.S. soldier. In the third case, a U.S. soldier shot and killed an Iraqi when he lunged at another U.S. soldier, the official said.

In the four cases of justifiable homicide, there were a total of eight detainee deaths. Three of the four cases were at Abu Ghraib prison. In one of them, in November 2003, four Iraqis were killed. An April 2004 case at Camp Bucca (search) in southern Iraq resulted in two deaths. There also were cases at Abu Ghraib in April 2003 and March 2004 that each involved one death.