The U.S. military said on Friday it had started a criminal investigation into the deaths last month of three men in the custody of U.S.-led forces in Iraq.
Several U.S. soldiers were apparently involved in the deaths, which were witnessed by other soldiers who reported the incident, military sources at the Pentagon told NBC's Jim Miklaszewski.
"It doesn't look good" for those men being investigated, one of the sources said.
Lt. Gen. Peter Chiarelli, commander of multinational forces in Iraq, ordered the investigation into the deaths, which occurred on or around May 9 in Salahaddin, a province north of Baghdad.
“The request for an investigation is the result of soldiers’ reported suspicions about the deaths,” said the statement.
The investigation is taking place amid another probe of allegations that U.S. Marines killed up to 25 unarmed civilians in the town of Haditha last year.