Sgt John Russell's family has released a photo of him

A US soldier has been charged with five counts of murder a day after five fellow soldiers were shot dead at a military counselling clinic in Iraq.

Sgt John Russell was also charged with one count of aggravated assault, spokesman Maj Gen David Perkins said.

Sgt Russell, serving with the 54th Engineering Battalion based in Germany, was taken into custody after the shooting in Camp Liberty, Baghdad.

One Navy doctor, an Army doctor and three enlisted personnel were killed.

The clinic provides troops with help for personal issues or combat stress.

Weapon confiscated

Maj Gen Perkins said Sgt Russell had been referred to the clinic by his superiors, and that his weapon had been taken away about a week before the incident.

Details of the shooting are still unclear.

"We have many different accounts into exactly what happened," Maj Gen Perkins said.

Sgt Russell was "probably" on his third tour of duty in Iraq, but was due to return home soon, officials said.

An inquiry is under way into whether there are sufficient mental health facilities in Iraq for troops.

Almost one in five US soldiers deployed in Iraq suffer from Post-Traumatic Stress Disorder, according to the US military's Battlemind website.

Incidents of US troops shooting fellow soldiers are rare.

The last such reported incident took place on 14 September 2008, when Sergeant Joseph Bozicevich allegedly shot dead two of his superior officers. This case is still being investigated.

Monday's shooting was the deadliest single incident involving US forces since 10 April, when five soldiers were killed by a truck bomb in the northern city of Mosul.