Syrian rebel commander Hassan Abdul Ghany said early on Sunday that insurgent forces "fully liberated" Syria's central city of Homs.
This comes after Abu Mohammed al-Golani, leader of the Islamist rebel group Hayat Tahrir al-Sham, a former al Qaeda affiliate, said in a video message on Saturday that the rebels are "in the final moments of liberating" Homs.
Golani called it a "historic moment" and called on his fighters not to harm "those who drop their arms."
The rebels also claimed to have freed over 3,500 inmates from Homs military prison (Baluni prison), posting a video of it to their Telegram channel.
Dozens of fighters from Hezbollah's elite Radwan forces fled Homs after a decision was taken with the Syrian army that the city could no longer be defended, a Syrian army officer told Reuters on Saturday.
Syrian government forces abandoned the key city of Homs on Saturday after less than a day of fighting, leaving President Bashar al-Assad's 24-year rule dangling by a thread with insurgents also advancing towards the capital Damascus.
Since the rebels' sweep into Aleppo a week ago, government defenses have crumbled at dizzying speed as rebels seized a string of major cities and reignited a rebellion in places it had long seemed dead.
The fall of Homs and threat to the capital now pose an immediate existential danger to the Assad dynasty's five-decade reign over Syria and the continued influence there of its main regional backer, Iran.
The most powerful insurgent leader, Abu Mohammed al-Golani, said in a statement that rebels were on the cusp of taking the whole country and "the end of the criminal regime is near."
Verge of collapse
Assad's government may be on the verge of collapse, foreign officials told Reuters on condition of anonymity. One U.S. official put the potential timeframe at five to 10 days while another said Assad could be ousted in the coming week. A Western official agreed with the latter assessment.
Seizing Homs, an important crossroads between the capital and the Mediterranean, effectively cuts off Damascus from the coastal stronghold of Assad's minority Alawite sect, and from Russia's air and naval base.
The Syrian army and security commanders left Homs on Saturday by helicopter for the coast while a large military convoy withdrew by land, a senior army officer said. Rebels said they were entering the city center.
Thousands poured onto the streets there to celebrate, residents said.
Homs residents and rebels said the insurgents had captured the central prison and were freeing thousands of detainees. Residents said state security and intelligence personnel had evacuated their offices after burning papers.
Insurgents have seized almost the entire southwest within 24 hours, and they have advanced to within 30 km (20 miles) of Damascus as government forces fell back, rebels said.
Underscoring the possibility of an uprising in the capital, protesters took to the streets in several Damascus suburbs, ripping up Assad posters and tearing down a statue of his father, former President Hafez al-Assad, uncontested by army or police. Some were joined by soldiers who had changed into civilian clothes and deserted, residents said.
However, the state news agency reported that Assad remained in Damascus, and the military said it was reinforcing around the capital and south.