Afghan security forces are continuing to surround a notorious high-security jail where an uprising by up to 2,000 prisoners is under way.
Security forces are not able to enter the prison
Taleban and al-Qaeda members as well as ordinary criminals are involved.
Sources told the BBC that seven people have been killed and 36 hurt in the rioting, although officials deny this.
Scores of Afghan soldiers have surrounded Kabul's Pul-e-Charkhi jail. Negotiation attempts by loudspeaker have so far failed.
The BBC's Bilal Sarwary, outside the prison, said US and Nato forces were also at the scene, and that two drones were circling overhead.
Afghan army rapid-reaction troops had arrived on the scene earlier.
A senior prison official told the BBC that he was "concerned" that some 1,350 prisoners who had "taken control" of a women's wing may have raped some of the inmates.
"We really do not know how many people are killed or injured since we cannot enter the area," he said.
Though gunshots were heard within the prison walls on Sunday, no gunfire could be heard on Monday morning.
Trouble apparently started at about 2200 (1730 GMT) on Saturday in Block 2 - which houses 1,300 inmates - after a change in prison uniform rules.
By Sunday evening local time, up to 750 inmates jailed for ordinary criminal offences in another block had begun burning furniture in support of the Block 2 prisoners.
Some reports said the riot developed into an escape attempt, with prisoners trying to get over the walls.
An official told the BBC that Taleban and al-Qaeda elements were responsible for the violence.
"It's the work of al-Qaeda and Taleban. By making things violent, they want to escape the prison. So far no-one has succeeded doing this," Gen Salam Bakhshi, director of Afghan prisons, told the BBC.
An Afghan MP denounced any use of gunfire to quell the unrest, and called for "immediate, peaceful negotiations".
"It's the government's mistake," Dr Assadullah Hymatyar said. "When they decided to give uniforms to the prisoners they should have done it by peaceful means, not through imposition and force."
Parliament is due on Monday to ask the government for an explanation of the events.
Negotiations by loudspeaker had apparently failed to make a breakthrough.
Prison guards said four or five people had been wounded, but the rioters told the authorities there were many more.
"They have control of the wounded prisoners and they are not giving them to us so that we can treat them. We have doctors and ambulances ready here," said Afghanistan's deputy justice minister, Mohammad Qasim Hashimzai.
Hundreds of prisoners remain barricaded inside a women's wing, our correspondent says.
A senior official told him that two female prison guards had been taken hostage by prisoners.
Pul-e-Charkhi is a huge prison complex built in the 1970s on the outskirts of the capital.
Correspondents say the vast and run-down jail is notorious for the disappearance and torture of thousands of Afghans during the communist era.
Last month, seven Taleban suspects escaped from the jail, with prison guards accused by officials of helping the break-out.
Four men described as "dangerous militants" escaped from US custody at the Bagram air base near Kabul last year.