Syria is on the brink of civil war as rebels raced to fill a power vacuum left by ousted despot Bashar al-Assad.

His brutal 24-year reign of terror was ended by an Islamist anti-government offensive forcing him and his family to flee.

The lightning-fast coup toppled his military regime in hours, but what comes next has the world nervously watching as players in the powder-keg Middle East jostle for position.

Thousands poured onto the streets after the army withdrew, dancing and chanting: "Assad is gone, Homs is free".

Colonel Richard Kemp, the decorated former British Army commander, said: “No one has any real idea how this situation will develop and could see Syria becoming an Afghanistan-style base for global jihad, threatening us all. Rebels will have access to massive weapons stockpiles, including chemical weapons, tanks, and planes.

The whereabouts of Assad, 59, who trained as a surgeon at Western Eye Hospital in London in the early nineties, and his wife Asma and two children remain unknown.

Amid the chaos, the Islamist militant group Hayat Tahrir al-Sham has emerged as a successor to the regime.

Its leader, Abu Mohammed al-Jawlani, stated on Syrian state TV that there is "no room" for turning back and that "the future is ours".

It was set up in 2011 as a direct affiliate of al-Qaeda under the name of Jabhat al-Nusra and remains a proscribed terrorist group by the UN and the US.

The extraordinary events were described as a new birth for "great Syria”, moving from a “struggle to overthrow the Assad regime to the struggle to build a Syria together that befits the sacrifices of its people”.

UK Prime Minister Sir Keir Starmer welcomed the fall of Bashar al-Assad's "barbaric regime" but urged for "peace and stability" in the country.

He said: “The developments in Syria are unprecedented, and we are speaking to our regional partners and monitoring the situation closely.

"The Syrian people have suffered under Assad's barbaric regime for too long, and we welcome his departure."

The toppling of Assad is a huge embarrassment to Russia, a key ally which provided the military firepower to help him remain in power.

Russia confirmed the ousted Kremlin-backed dictator had left the country following negotiations with "other participants in the armed conflict”.

Moscow said it was not involved in the negotiations, and its military bases in Syria remained on high alert but were not under threat. Rumours that Assad had fled to Moscow were unconfirmed.

The Assad family had ruled Syria for 53 years, running the country as a personal fiefdom, with Assad seizing power in 2000 after the death of his father, who had ruled for almost three decades.

What made the past 48 hours remarkable was the ease at which his iron rule was overthrown.

Just 13 years ago, with weapons and hardware supplied by Russia, Assad was able to crush a peaceful, pro-democracy uprising which spiralled into civil war. More than 500,000 people were killed and 12 million displaced.

Until recently, Assad’s military, along with Russian air support, battled Hayat Tahrir al-Sham [HTS], a coalition of Islamist militant groups in northwest Syria. Meanwhile, the Kurdish-dominated Syrian Defence Forces, which controlled most of northeastern Syria, regularly clashed with Arab tribes that accused the group of discrimination.

Turkey and its proxies also control areas along the northern border, while factionalised fighting allowed space for the self-proclaimed Islamic State to launch attacks.

America has at least 900 military personnel in Syria on counter-terrorism operations, while Israel has regularly targeted Iranian and Syrian military positions in Syria. In the wake of last year’s October 7 massacre, it hit Damascus and Aleppo airports.

Last week, HTS successfully led a major offensive in the northwest, which was aided by rebel factions.

They seized Aleppo, Syria's second-largest city, before sweeping south to capture the capital, Damascus, as the Syrian military folded.

The end of President Assad's iron rule has failed to end bitter divisions within Syria but marks a seismic shift in the region.

Syria is a key strategic location in the Middle East, and there are now heightened fears as to what follows, with experts pointing to the aftermath of Iraq following the capture of Saddam Hussein in 2003 and Libya after the fall of Muammar Gaddafi in 2011, which both sparked years of bloodshed and civil war.

Former Tory MP, Defence Select Committee chairman and Royal Green Jackets soldier Tobias Ellwood said: “What Syria needs is a short-term technocratic government to stabilise the situation and prevent full-scale civil war, followed by a federated model that reflects the country's diverse patchwork of sectarian and ethnic regions. Get this right and Syria could finally move toward a more stable future.

“Get it wrong, and the country risks imploding, paving the way for the increased movement of drugs, refugees, modern slaves, and weapons across the region.

“The consequences of failure would be felt far beyond Syria's borders, with another wave of refugees fleeing toward Europe, a breeding ground for Islamic terrorism and an ever-turbulent Middle East spilling over into global instability. Once again, Syria calls for international help. The question is: will the world blink again?”

Alp Mehmet, Chairman of Migrationwatch UK, said: “We can expect tens, if not hundreds, of thousands of those displaced, or who flee from the new regime, to make their way to the EU and the UK - both legally and illegally. Many will want to join the 20,000 who came in 2015/16 as part of the Syrian resettlement scheme.”

Tension in Syria has been bubbling for more than a decade.

What started as relatively small-scale protests against Assad’s regime in 2011 grew into a full-scale war between the Syrian government, backed by Russia and Iran, and anti-government rebel groups backed by America and allies including Saudi Arabia, Turkey, Jordan, and the United Arab Emirates. Driving the conflict were coalition efforts to defeat the self-proclaimed Islamic State, violence between the Syrian government and opposition forces, and military operations against Syrian Kurds by Turkish forces.

Speaking to the Express about the wider implications of the toppling of Assad, Col Kemp said: “This is a major blow for Iran. Syria was their client and a key element of the ring of fire strategy against Israel. Iran will now be working to try to cultivate the rebels for their own purposes.”

“The other direct blow for Iran is that it cuts off what is left of Hezbollah which previously had supply routes from Iran via Syria. Hezbollah is now isolated.

“Jordan will be under direct threat from the Islamist regime in Syria.

“Russia will be weakened and humiliated. They have been unable to save the Assad regime. Their presence and influence in Syria was a major element of Russian prestige. It is not clear what they will now do.

“The major winner is Turkey, which may now be able to deal more effectively with the Kurds in Syria, which is a major interest for them in the Middle East. Given their relationship with HTS and other rebel groups, they will now gain greatly increased influence in the Middle East.”

Arwa Damon, President and founder of the International Network for Aid, Relief, and Assistance, said: “There is no doubt in anyone’s mind that the era of al-Assad is finished.

“Even when people left Syria and were ostensibly in a safe country, they were still afraid in many cases to actually publicly speak out about the al-Assad regime.

“The fear of the regime, the fear of detention, the fear of what happened inside this darkened ominous prison system, the fear of just disappearing was so real that it permeated every single person’s fibre of being.”