Washington ? The military has charged four U.S. soldiers with abusing prisoners of war in Iraq. The soldiers and their families deny the accusations.

The four military police from a Pennsylvania-based Army Reserve unit are accused of punching, kicking and breaking bones of prisoners at Camp Bucca, the largest U.S.-run POW camp in Iraq.

The soldiers, charged this month, are the first U.S. troops known to face charges of abusing prisoners during the Iraq conflict.

The military’s investigation continues, said Lt. Cmdr. Nick Balice, a spokesman for U.S. Central Command. Balice confirmed four soldiers had been charged as part of that investigation but said he could not release their names.

The Associated Press obtained the identities of those charged, as well as the specific allegations against them, in interviews Saturday with the parents of all four.

The soldiers say their actions were in self-defense when Iraqi prisoners attacked them.

“A few of my MPs were assaulted by the enemy prisoners, and we had to use force to regain control, all justifiable,” one of the accused, Staff Sgt. Scott McKenzie, e-mailed to relatives five days after the May 12 incident.

The four are not jailed but have been given restricted duties, separated from each other and assigned to a base in Kuwait, away from the rest of their unit. Military authorities told the four this month to quit talking about the case, relatives said.

Family members say they are worried about the stress on the four soldiers.

Iraqi prisoners of war walk toward the gates of Camp Bucca in Umm Qasr, southern Iraq before being released by U.S. troops in this May 6 file photo. The military has charged four U.S. soldiers from a Pennsylvania-based Army Reserve unit with abusing prisoners of war in Iraq. The soldiers and their families deny the accusations.

“If one of them commits suicide, if one of them gets killed, somebody has to answer for that,” said Carol Graff, mother of accused Master Sgt. Lisa Girman.

The soldiers are awaiting an Article 32 hearing, a military proceeding where prosecutors lay out evidence of a crime and a commander decides whether to convene a court-martial. At least three other soldiers from the 320th Military Police Battalion also are being investigated, relatives said. The unit is based in Ashley, Pa., a suburb of Wilkes-Barre.

“I can’t believe they’re treating the soldiers this way,” said Linda Edmondson, mother of accused Sgt. Shawna Edmondson. “All they did was go help transport prisoners, and they are charged with this.”