Syrians celebrate the taking over of the capital Damascus by Syrian rebel fighters in Beirut's Triq al Jdideh neighbourhood on December 8, 2024. Islamist-led rebels declared that they have taken Damascus in a lightning offensive on December 8, 2024 sending President Bashar al-Assad fleeing and ending five decades of Baath rule in Syria. [AFP]

Syrian rebels swept into Damascus on Sunday declaring they had toppled "tyrant" President Bashar al-Assad, whose current whereabouts are unknown after he reportedly fled the country.

Here's what we know about where Assad could be, what happened to his country's army and who is in charge now after decades of rule by the president's family.

How did Assad flee?

The Syrian Observatory for Human Rights war monitor said Assad left on a private plane that took off from Damascus international airport at 10:00 pm (1900 GMT) on Saturday night, without specifying where he headed.

After that, the army and security forces pulled out of the airport, with commercial flights already suspended earlier, added the Britain-based Observatory, which relies on a network of sources on the ground.

The rebels, who began a lightning offensive on October 27, quickly announced they had toppled "tyrant" Assad and that Damascus was a "free" city, calling on millions of Syrians who fled the war for safety abroad to return home.

Assad's location was not clear on Sunday morning, but Observatory chief Rami Abdel Rahman told AFP there were three main possibilities.

The first was that Assad headed to Russia, which over the years has provided key military, political and diplomatic support for the Syrian leader, including with its air power.

Second that he fled to his other main ally Iran, which has sent military advisers to Syria and supported fighters, including from Lebanon's Hezbollah, who have been on the battlefield alongside government soldiers.

The third option, Abdel Rahman said, is that Assad went to the United Arab Emirates, the first Arab Gulf country to restore broken ties with Damascus in 2018 after they were severed following the war's outbreak in 2011.

Syrian anti-government fighters celebrate as they pour into the captured central-west city of Hama on December 6, 2024. In little over a week, the offensive by rebel forces has seen Syria's second city Aleppo and strategically located Hama fall from President Bashar al-Assad's control for the first time since the civil war began in 2011. [AFP]

What about the Syrian army? 

As news of Assad's departure spread, army soldiers in various parts of the capital Damascus began shedding their military clothes, local residents told AFP.

One eyewitness, requesting anonymity, told AFP they saw dozens of military vehicles abandoned in the upscale Mazzeh district, home to military and security headquarters, embassies and United Nations offices.

The army has not issued an official statement, but soldiers told AFP they were told to leave their positions, with one saying "our direct superior told us to leave and go home, so we knew it was over."

On the highway between the central city of Homs and Damascus, an AFP correspondent saw hundreds of soldiers gathered near rebel checkpoints.

Hundreds of soldiers and rebel fighters have been killed since the offensive began, with fierce battles in the country's north particularly in the first few days.

But government forces withdrew from their positions with no major resistance in some areas, according to the Observatory.

The rebels swiftly took control of several strategic cities within days, starting from second city Aleppo, then central Hama and Homs before marching on the capital.

Thirteen years of civil war have exhausted Syria's military equipment and army, which has lost around half of its personnel, estimated at 300,000 before 2011.

Syrian antigovernment fighters patrol the captured central-west city of Hama on December 6, 2024. In little over a week, the offensive by rebel forces has seen Syria's second city Aleppo and strategically located Hama fall from President Bashar al-Assad's control for the first time since the civil war began in 2011. [AFP]

In recent days, analysts have emphasised the military's weakness on the battlefield, without effective Russian or Iranian support.

A source close to Lebanon's Hezbollah told AFP the Iran-backed group had withdrawn from positions in the vicinity of Damascus and in a border area with Lebanon, where it had bases and depots.

Who holds power?

Syrian Prime Minister Mohammed al-Jalali, who took up the post in September, said in a message broadcast on his Facebook page that he was ready to "cooperate" with the leadership chosen by the Syrian people and for any handover procedures.

The rebel factions announced a "new era" in Syria.

The leader of Syrian rebel group Hayat Tahrir al-Sham, Abu Mohammed al-Jolani, ordered forces Sunday not to approach official institutions in Damascus, saying they would remain under the prime minister until they are officially handed over.

In the statement on Telegram, Jolani used his real name Ahmed al-Sharaa instead of his more well-known nom de guerre.

With the army's collapse in areas it controlled, including around critical facilities, the rebels and other armed groups who control swathes of the country face major challenges.

Mohanad Hage Ali from the Carnegie Middle East Center said on X, that "the main challenge today lies in re-building the Syrian state and shifting from the chaos and fragmentation phase."

"Until now, the factions have shown awareness in dealing with minorities and prisoners," he said, amid hope this could help translate "into the reconstruction of state institutions".