After three days of intense fighting, rebel forces have entered the country's fourth largest city, Hama, which previously had nearly one million inhabitants.
Early on Thursday, the forces had begun to advance on several fronts in the city's outskirts, according to the conflict monitor Syrian Observatory for Human Rights (SOHR), which monitors the fighting in Syria from the UK.
The rebels, who consist of many extreme Islamist groups, also claim to have taken control of a prison and released large numbers of prisoners.
"Major losses"
Syria's regular army, which is under the command of Bashar al-Assad's regime in Damascus, announces that it is withdrawing from the city's central areas to positions outside. In a statement on social media, the army leadership writes that the fighting escalated on Thursday and that an increasing number of its soldiers were killed.
"The groups were able to push forward in several directions towards the city and enter it, despite suffering major losses," the army's account reads.
Abu Mohammed al-Jawlani, leader of the extreme Islamist group Hayat Tahrir al-Sham (HTS), claims that the rebel forces have entered Hama "to cleanse the wound that has existed in Syria for 40 years".
Student Maya stayed at home with her family while the fighting raged.
We have continuously heard the sounds of explosions and gunfire, she tells AFP.
We do not know what is happening outside.
On Thursday afternoon, the military reports that an enemy drone and two other projectiles have been shot down over Damascus. No casualties have been reported.
Surprise offensive
Last week, rebel groups led by HTS took control of the metropolis Aleppo in a surprise offensive where government forces were initially quickly pushed back. During the continued advance along a motorway south, the rebel forces have been attacked by Syrian and Russian military aircraft.
If Hama falls, it means the beginning of the regime's fall, SOHR chief Rami Abdul Rahman told AP earlier on Thursday, before it became clear that it had happened.
The next target may be Homs, which is the country's third largest city and is located about four miles south of Hama, according to analysts.
During the past week's escalated conflict, at least 700 people have been killed, according to a compilation published by SOHR on Wednesday. Then, about 110 of the fatalities were said to be civilians.
A hundred thousand people have been driven to flee in the provinces of northwestern Syria, the UN reported on Wednesday.
