The Syrian army says it has withdrawn from the central city of Hama after insurgents broke through its defences, in another setback for President Bashar Assad.
The announcement on Thursday came hours after opposition fighters said they had entered the city and were marching toward the centre.
The army said it redeployed from Hama and took positions outside the city to protect the lives of civilians.
The capture of Syria’s fourth largest city is another blow for Mr Assad days after insurgents captured much of Aleppo, the country’s largest city.
The Syrian army said in a statement later that a number of troops were killed after resisting the insurgents for days. It accused the attackers of relying on suicide attacks to break through the defences of the city.
Hama is one of the few cities that remained under full government control during Syria’s conflict, which broke out in March 2011 following a popular uprising. Its capture would be a major setback for Mr Assad.
The offensive is being led by the jihadi group Hayat Tahrir al-Sham, as well as an umbrella group of Turkish-backed Syrian militias called the Syrian National Army.
Their sudden capture of the northern city of Aleppo, an ancient business hub, was a stunning prize for Mr Assad’s opponents and reignited the conflict which had been largely stalemated for the past few years.
The next target of the insurgents is likely to be the central city of Homs, the country’s third largest.
Homs is about 40 kilometres (25 miles) south of Hama.
Intervention by Russia, Iran, Iranian-allied Hezbollah and other militant groups has allowed Assad to remain in power.
The latest flare-up in Syria’s long civil war comes as Mr Assad’s main regional and international backers are preoccupied with their own wars.
Tens of thousands of people have been displaced by the renewed fighting, which began with the surprise opposition offensive on November 27.
The insurgents claimed on their Telegram channel on Thursday that they had entered Hama and were marching toward its centre.
“Our forces are taking positions inside the city of Hama,” the channel quoted a local commander identified as Major Hassan Abdul-Ghani.
The Britain-based Syrian Observatory for Human Rights, an opposition war monitor, said fierce battles were fought inside Hama.
“If Hama falls, it means that the beginning of the regime’s fall has started,” the Observatory’s chief, Rami Abdurrahman, told The Associated Press before the city’s capture.
It is about 200 kilometres (125 miles) north of the capital, Damascus, which is Mr Assad’s seat of power.
Hama province also borders the coastal province of Latakia, a main base of popular support for Mr Assad.
The city’s name is known for the 1982 massacre of Hama, one of the most notorious in the modern Middle East, when security forces under Mr Assad’s late father, Hafez Assad, killed thousands to crush a Muslim Brotherhood uprising.
