The Syrian regime lost control Friday of the symbolic southern city of Daraa and most of the eponymous province, which was the cradle of the country's 2011 uprising, a war monitor said.
"Local factions have taken control of more areas in Daraa province, including Daraa city... They now control more than 90 percent of the province, as regime forces successively pulled out," the Syrian Observatory for Human Rights said.
In Daraa province, only the Sanamayn area is still in government hands, Rami Abdel Rahman, who heads the British-based monitor with a network of sources in Syria, told news agency AFP.
Earlier Friday, local factions seized the Nassib-Jaber border crossing with Jordan, the Observatory said, with Jordan closing its side of the crossing, Interior Minister Mazen al-Faraya said.
Daraa province was the cradle of the 2011 uprising against Syrian President Bashar al-Assad's rule, but it returned to regime control in 2018 under a ceasefire deal brokered by Assad ally Russia.
It was a rebel bastion at the height of the civil war in the early 2010s.
Former rebels there who accepted the 2018 deal were able to keep their light weapons.
Daraa province has been plagued by unrest in recent years, with frequent attacks, armed clashes and assassinations, some claimed by the Islamic State group.
Syria's civil war, which began with Assad's crackdown on democracy protests, has killed more than 500,000 people and forced more than half the population to flee their homes.
Never in the war had Assad's forces lost control of so many key cities in such a short space of time.
Since a rebel alliance led by Hayat Tahrir al-Sham (HTS) launched its offensive on November 27, the government has lost second city Aleppo and subsequently Hama in central Syria.
The rebels were on Friday at the gates of Homs, Syria's third city, as the government pulled out its troops from Deir Ezzor in the east.
The rebels launched their offensive the same day a ceasefire took effect in neighbouring Lebanon in the war between Israel and Hezbollah.
The Lebanese group has been an important Assad ally, alongside Russia and Iran.
Turkey, which has backed the opposition, said it would hold talks with Russia and Iran in Qatar this weekend.
Ahead of the talks, the foreign ministers of Iran, Iraq and Syria met in Baghdad, where Syria's Bassam al-Sabbagh accused the government's enemies of seeking to "redraw the political map".
Iran's Abbas Araghchi pledged to provide Assad's government with "whatever (support) is needed".
But Tehran has started to withdraw its military commanders and personnel, including some diplomatic staff, from Syria, the New York Times reported Friday, citing unnamed regional officials and three Iranian officials.