Syrian rebels ousted pro-government forces from Hama on Thursday, bringing the insurgents a major new victory after a lightning advance across northern Syria and dealing a new blow to President Bashar al-Assad and his Russian and Iranian allies.

The Syrian army announced that the rebels had entered Hama after intense clashes and said it was redeploying outside the city “to preserve civilians lives and prevent urban combat.”

Rebels said they had taken districts in the city's northeast and had seized the central prison, freeing detainees.

Al Jazeera television broadcast what it said were images of rebels inside the city, some of them meeting civilians near a roundabout while others drove in military vehicles and on mopeds.

The rebels took the main northern city of Aleppo last week and have since pushed south from their enclave in northwest Syria, reaching a strategic hill just north of Hama on Tuesday and advancing towards the city's east and west flanks on Wednesday.

Hama has remained in government hands throughout the civil war, which erupted in 2011 as a rebellion against President Bashar al-Assad. Its fall to a revived insurgency would send shockwaves through Damascus and its Russian and Iranian allies.

The city lies more than a third of the way from Aleppo to Damascus and its capture would open the road for a rebel advance on Homs, the main central city that functions as a crossroads connecting Syria’s most populous regions.

Inside Hama, the scene of an Islamist uprising that the Assad dynasty crushed in 1982, the internet was cut off and streets emptied on Wednesday according to a resident whose family remain in the city.