Syrian President Bashar al-Assad has left office and departed the country after giving orders there be a peaceful handover of power, the Russian Foreign Ministry said on Sunday – after Islamist-led rebels declared they had taken Damascus in a lightning offensive. 

Images from Damascus showed rebels firing into the air at sunrise, with some flashing the victory sign and crying "Allahu akbar" or "God is greatest." Some climbed atop a tank in celebration, while others defaced a toppled statue of Assad's father, Hafez.

Rebel factions aired a statement on Syrian state television saying they had toppled Assad as they called on fighters and citizens to safeguard the "property of the free Syrian state."

The president's departure ends five decades of Baath Party's governance in Syria and comes less than two weeks after the Islamist Hayat Tahrir al-Sham (HTS) group launched its campaign.

"After 50 years of oppression under Baath rule, and 13 years of crimes and tyranny and (forced) displacement... we announce today the end of this dark period and the start of a new era for Syria," the rebel factions said on Telegram.

The head of the UK-based Syrian Observatory for Human Rights, Rami Abdel Rahman, said: "Assad left Syria via Damascus international airport before the army security forces left" the facility. International news agencies have as yet been unable to immediately confirm the reports.

Prime Minister Mohammed al-Jalali said he was ready to cooperate with "any leadership chosen by the Syrian people".

"This country can be a normal country that builds good relations with its neighbors and the world... but this issue is up to any leadership chosen by the Syrian people," Jalali said in a speech broadcast on his Facebook account.

The rapid developments in Damascus came only hours after HTS said it had captured the strategic city of Homs, on the way to the capital. 

Homs, known during the early years of the civil war as the "capital of the revolution," is about 140 kilometres from the capital and was the third major city seized by the rebels, who began their advance on November 27, reigniting a years-long war that had become largely dormant.

The Observatory said Daraa, the cradle of the 2011 uprising, also fell from government control.

World reaction

China's foreign ministry said Sunday it hopes Syria "returns to stability as soon as possible," saying Beijing "is closely following the development of the situation in Syria and hopes that Syria returns to stability as soon as possible.

"The Chinese government has actively assisted Chinese citizens who are willing to leave Syria in a safe and orderly way, and has maintained contact with... Chinese citizens who remain in Syria," the ministry said.

"We urge the relevant Syrian parties to take practical measures to ensure the safety of Chinese institutions and personnel in Syria," it added.

A senior United Arab Emirates official urged Syrians to collaborate to avert "chaos" as the country resets.

"We hope that the Syrians will work together, that we don't just see another episode of impending chaos," presidential adviser Anwar Gargash said at the Manama Dialogue in Bahrain.

Gargash refused to confirm or deny speculation Assad would take shelter in the UAE.

"When people ask, 'where is Bashar al-Assad going to?', this is really at the end of the day a footnote in history," he told the forum. 

The Israeli military said it had deployed forces to a demilitarized buffer zone in southwest Syria abutting the Israeli-annexed Golan Heights, citing "the possible entry of armed individuals into the buffer zone."

"Following the recent events in Syria... the IDF (army) has deployed forces in the buffer zone and in several other places necessary for its defence, to ensure the safety of the communities of the Golan Heights and the citizens of Israel," a military statement said.

Iranian state TV said Iran's embassy in Syria was "attacked" on Sunday. "Unknown individuals have attacked the Iranian embassy," a state TV broadcaster said, showing footage from Al Arabiya, said to be from the diplomatic compound. Authorities in Iran have yet to comment on Assad's fall.

Türkiye's Foreign Minister Hakan Fidan acknowledged that "control of the country is changing hands," adding that "this didn't happen overnight. For the last 13 years, the country has been in turmoil" since civil war began in 2011. 

Fidan said Türkiye is in contact with Syrian rebels to ensure security and insisted that any new administration must not "pose a threat" to neighbors.

"We have to work very hard... with Syrian people, not just Türkiye, but also regional actors, international actors, to make sure that there is a good and smooth transition period, no more harm to the civilian people," Fidan said at the Doha Forum in Qatar.

Jordan has urged its citizens to leave neighboring Syria "as soon as possible", as have the United States and Russia, which both keep troops in Syria.

An Iraqi security source told AFP that Baghdad had allowed in hundreds of Syrian soldiers who "fled the front lines" through the Al-Qaim border crossing. A second source put the figure at 2,000 troops, including officers.

In Greece, the Syrian opposition flag was unfurled at the Syrian embassy. Greek state news agency ANA said at least three men had entered the Athens embassy and unfurled the flag, which was seen hanging from the roof of the building. Officers were sent to the scene and three men were detained, it added.