US troops killed at Kabul prison

Pul-e-Charkhi lies on the eastern outskirts of Kabul

Two US soldiers have been shot dead by a man dressed in Afghan army uniform outside a prison on the outskirts of Kabul, Afghanistan, US military said.

The man shot at vehicles leaving the high-security Pul-e-Charkhi prison east of the capital on Sunday, injuring two other US soldiers in the attack.

The gunman was killed by Afghan troops stationed outside the jail who came to the aid of the US soldiers.

The motive for the attack is being investigated.

The victims have not yet been identified.

Infamous jail

Major Sheldon Smith said it initially appeared that the man was a rogue soldier, but this has not yet been confirmed.

"He fired shots into a vehicle being driven by US service personnel as they were leaving the prison. This action resulted in the death of two soldiers and left two other soldiers wounded," Major Smith said.

He explained that the US soldiers were deployed at the prison as mentors to Afghan troops, helping provide external security.

The Associated Press news agency reported the soldiers were also helping set up a new high-security wing designed to house Afghans transferred from Guantanamo Bay.

Pul-e-Charkhi is a huge prison complex built in the 1970s on the outskirts of the capital.

The vast and run-down jail is infamous for disappearances and torture during the Communist era.

It is now used to house common criminals and al-Qaeda and Taleban suspects.