“I ask God almighty that it be a conquest with no revenge,” Jolani, of the Hayat Tahrir al-Sham group which leads the rebel alliance, said in a video message.

The message came on the Telegram channel of the rebel factions’ joint operations room, after announcing the fighters had entered Hama “to cleanse the wound that has endured in Syria for 40 years”.

Syria’s army acknowledged on Thursday that it had lost control of the strategic central city of Hama for the first time since war broke out in 2011, amid a lighting rebel offensive.

The rebels said on Telegram that “our forces entered Hama central prison and liberated hundreds of prisoners”.

The loss of Syria’s fourth-largest city, which saw major demonstrations against President Bashar al-Assad in 2011, just days after the fall of Aleppo, is a blow to the government.

In recent years with Russian and Iranian support, Assad had clawed back territory lost earlier in the conflict.

In 1982, in a chapter that remains among the darkest in the country’s bloody history, the Syrian government cracked down in Hama on an uprising by the Muslim Brotherhood.

The group was at the time the main opposition to then-president Hafez al-Assad, father of the current president, and carried out several attacks.

In February 1982, Brotherhood members killed cadres of the ruling Baath Party in Hama, triggering brutal reprisals during a military offensive to quell the uprising using artillery and tanks.

Various sources estimate the deaths between 10,000 and 40,000 in the besieged and isolated city over about one month.

Hafez al-Assad’s brother, Rifaat, carried out the repression as head of the “Defence Brigades”, an elite force of the authorities.

The action earned him the nickname, “Butcher of Hama.”