Beirut. The head of a Syrian opposition war monitor said early Sunday that President Bashar Assad left the country for an undisclosed location, fleeing ahead of insurgents who said they had entered Damascus after a stunning advance across the country.

Rami Abdurrahman of the Syrian Observatory for Human Rights told The Associated Press that Assad took a flight Sunday from Damascus.

Residents of the capital reported sounds of gunfire and explosions. Footage broadcast on opposition-linked media showed a tank in one of the capital's central squares while a small group of people gathered in celebration. Calls of “God is great” rang out from mosques.

It was the first time opposition forces had reached Damascus since 2018, when Syrian troops recaptured areas on the outskirts of the capital following a years-long siege.

There was no immediate statement from the Syrian government. The pro-government Sham FM radio reported that the Damascus airport had been evacuated and all flights halted.

The insurgents also announced they had entered the notorious Saydnaya military prison north of the capital and “liberated" their prisoners there.

The night before, opposition forces took the central city of Homs, Syria's third largest, as government forces abandoned it. The city stands at an important intersection between Damascus, the capital, and Syria’s coastal provinces of Latakia and Tartus -- the Syrian leader’s base of support and home to a Russian strategic naval base.

The government denied rumors that Assad had fled the country.

Sham FM reported that government forces took positions outside Homs without elaborating. Rami Abdurrahman who heads the Britain-based Syrian Observatory for Human Rights, said Syrian troops and members of different security agencies withdrew from the city, adding that rebels entered parts of it.

The insurgency announced later Saturday that it had taken over Homs. The rebels had already seized the cities of Aleppo and Hama, as well as large parts of the south, in a lightning offensive that began Nov. 27. Analysts said rebel control of Homs would be a game-changer.

The rebels' moves into Damascus came after the Syrian army withdrew from much of the southern part of the country, leaving more areas, including several provincial capitals, under the control of opposition fighters.

The fall of Damascus would leave government forces in control of only two of the 14 provincial capitals: Latakia and Tartus.

The advances in the past week were by far the largest in recent years by opposition factions, led by a group that has its origins in al-Qaida and is considered a terrorist organization by the United States and the United Nations. In their push to overthrow Assad's government, the insurgents, led by the Hayat Tahrir al-Sham group, or HTS, have met little resistance from the Syrian army.

The rapid rebel gains, coupled with the lack of support from Assad's erstwhile allies, posed the most serious threat to his rule since the start of the war.

The UN’s special envoy for Syria, Geir Pedersen, called Saturday for urgent talks in Geneva to ensure an “orderly political transition.” Speaking to reporters at the annual Doha Forum in Qatar, he said the situation in Syria was changing by the minute. Russian Foreign Minister Sergey Lavrov, whose country is Assad's chief international backer, said he feels “sorry for the Syrian people.”

In Damascus, people rushed to stock up on supplies. Thousands went to Syria's border with Lebanon, trying to leave the country. Lebanese border officials closed the main Masnaa border crossing late Saturday, leaving many stuck waiting.

Many shops in the capital were shuttered, a resident told The Associated Press, and those still open ran out of staples such as sugar. Some were selling items at three times the normal price.

The UN said it was moving noncritical staff outside the country as a precaution.

Assad's Status
Syria’s state media denied social media rumors that Assad left the country, saying he was performing his duties in Damascus.

He has had little, if any, help from his allies. Russia is busy with its war in Ukraine. Lebanon’s Hezbollah, which at one point sent thousands of fighters to shore up Assad's forces, has been weakened by a yearlong conflict with Israel. Iran has seen its proxies across the region degraded by regular Israeli airstrikes.

US President-elect Donald Trump on Saturday posted on social media that the United States should avoid engaging militarily in Syria. Separately, President Joe Biden’s national security adviser said the Biden administration had no intention of intervening there.

Pedersen said a date for talks in Geneva on the implementation of a U.N. resolution, adopted in 2015 and calling for a Syrian-led political process, would be announced later. The resolution calls for the establishment of a transitional governing body, followed by the drafting of a new constitution and ending with U.N.-supervised elections.

Later Saturday, foreign ministers and senior diplomats from eight key countries, including Saudi Arabia, Russia, Egypt, Turkey, and Iran, along with Pederson, gathered on the sidelines of the Doha Summit to discuss the situation in Syria.

In a statement, the participants affirmed their support for a political solution to the Syrian crisis “that would lead to the end of military activity and protect civilians.” They also agreed on the importance of strengthening international efforts to increase aid to the Syrian people.