Afghan security forces have sealed off the country's main high-security prison after days of unrest there.
Pul-e-Charkhi lies on the eastern outskirts of Kabul
Gunfire has been heard from the Pul-e-Charkhi prison, a huge complex built in the 1970s on the outskirts of the capital, Kabul.
Inmates are in control of parts of the prison and say they have taken two Afghan soldiers hostage.
Pul-e-Charkhi is now used to house common criminals as well as al-Qaeda and Taleban suspects.
Our correspondent says the stand off between prisoners and Afghan security forces, which began on Sunday, appears to be worsening.
Large numbers of soldiers and police have been arriving at the notorious jail which houses some of Afghanistan's most dangerous criminals and Taleban militants.
Inmates had taken control of sections of the building as part of a continuing protest against the authorities.
A number of prisoners contacted the BBC by mobile phone and said that seven inmates had been injured.
They also said that two Afghan national army soldiers had been captured and they would be killed unless mediators were sent in to resolve the dispute.
Our correspondent says it has not been possible to verify if the soldiers had been held.
There has been no official response from the Afghan government, but the defence minister told parliament an operation was being planned to raid the prison after parts of the building were overrun.
An Afghan member of parliament who visited the jail on Monday said the situation had become very tense.
The dispute has been going on for two weeks since an attempted jail-break and the arrest of a large number of prison visitors.
There have been sieges and riots in the past at the prison.
Four years ago the jail was raided by the military after some prisoners tried to escape.