STORY: Gunshots rang out in celebration across Syria's capital on Sunday (December 8), as rebel forces declared they had seized control of Damascus - and thrown out President Bashar al-Assad.

That spells an end to the Assad family's iron-fisted rule and comes after more than 13 years of civil war, in a seismic moment for the Middle East.

After mounting a sudden advance a week ago, the rebels on Sunday announced on state TV that they had toppled the president, calling him a tyrant.

The Syrian rebel coalition said in a statement it was working to complete the transfer of power to a transitional governing body with full executive powers.

It added that:

"The great Syrian revolution has moved from the stage of struggle to overthrow the Assad regime to the struggle to build a Syria together that befits the sacrifices of its people."

Assad, who had crushed all forms of dissent, flew out of Damascus for an unknown destination earlier on Sunday, according to army sources.

Russia's Foreign Ministry later said in a statement, Assad had left the country, after giving orders for a peaceful handover of power.

As people celebrated the government's collapse in cities such as Aleppo, Syrian Prime Minister Mohammad Ghazi al-Jalali said he had been in contact with rebel commander Abu Mohammed al-Golani to discuss managing the transitional period.

That marks a notable development in efforts to shape Syria's political future.

The prime minister also called for free elections so Syrians can choose the leaders they want.

But that would require a smooth transition in a country with complex competing interests, from Islamists to groups linked to the United States, Russia and Turkey.

Assad's ouster is a major blow to the influence of Russia and Iran in the region.

They were key allies who propped him up in the long-running conflict's critical moments.

The pace of events has stunned Arab capitals and raised fears of a new wave of regional instability.

It marks a turning point for Syria, shattered by years of war that has killed hundreds of thousands of people.

It has also forced millions abroad as refugees - many of them seen cheering on Sunday on the streets of their new homes, from Lebanon to Germany.

Western governments have long shunned the Assad-led state.

But now they have to decide how to deal with a new administration that looks set to be influenced by a group globally labelled as terrorists.

Led by the commander Golani, Hayat Tahrir al-Sham, or HTS, is Syria's strongest rebel group.

It used to be an al Qaeda affiliate and some Syrians are worried that it will impose draconian Islamist rule.