Syrian government forces stormed the central prison in Hama on Friday evening in an attempt to bring an end to a mutiny, according to a Syria monitor.

"They fired tear gas grenades inside the prison after arresting the families of prisoners gathered outside the building concerned about their fate," the Syrian Observatory for Human Rights told AFP.

Video footage posted on social networks which could not be independently verified showed a corridor filled with flames and smoke as a voice is heard giving the date as 6 May and the location as the central prison in Hama.

The sound of bursting tear gas grenades can be heard as inmates chant "Allahu Akbar!" (God is greatest) while others are heard coughing.

"There are reports of people falling unconscious and cases of suffocation," said Observatory chief Rami Abdel Rahman.

The mutiny began on Sunday when prison authorities tried to take five detainees to the military-run Saydnaya prison near Damascus, possibly for execution, according to a statement released on Friday by UN High Commissioner for Human Rights Zeid Ra’ad Al Hussein.

In reaction, several guards were taken hostage and prisoners took control of a section of the prison. Water and power supplies have since been cut.

"Hundreds of lives are at stake, and I call on the authorities to resort to mediation, or other alternatives to force," Hussein said in the statement.

"They should refer Syria to the ICC [International Criminal Court], so that there is a clear path to punishment for those who commit crimes like these.”

A video clip from earlier this week that also could not be independently verified purports to show prisoners inside the jail. At the end of the video, the man taping says they are protesting against death sentences given to their fellow prisoners.

Syrian activist group the Local Coordination Committees said about 800 prisoners, who are also protesting against conditions inside the jail, are involved.

The inmates are demanding trials, Abdel Rahman said.

Authorities have released 46 prisoners since the protest began, the Observatory said.

In a statement released on Friday, Syria's main opposition group, the High Negotiations Committee (HNC), called on international organisations "to intervene to prevent an imminent massacre" of prisoners.

The HNC urged the international community to "shoulder its responsibilities" and stop the government from carrying out "reprisals against the detainees".

France on Friday warned of "deadly reprisals from the regime" to end the mutiny and called on Damascus's allies to exert pressure "to avoid another massacre in Syria".

Last summer, Hama Central Prison saw a huge protest involving about 1,200 detainees who staged a sit-in demanding improvements in conditions. Prison authorities eventually backed down and the head of the facility was replaced.

More than 200,000 people have been imprisoned in government jails since 2011, according to the Britain-based Observatory, which relies on a wide network of sources inside Syria for its information.

Tens of thousands of political detainees are reported to have died of torture, of which the Observatory says it has verified 14,000 cases.

More than 270,000 people have died in the Syrian conflict since in started with the brutal repression of anti-government protests in 2011.