The Lebanese Army said on Sunday it was reinforcing its presence on the border with neighboring Syria, after the government of longtime President Bashar al-Assad fell and rebels took the capital Damascus.

Islamist-led rebels declared that they have taken Damascus in a lightning offensive on Sunday, sending President Bashar al-Assad fleeing and ending five decades of Baath rule in Syria.

Islamist-led rebels announced Sunday they had started entering the Syrian capital Damascus, where residents told AFP they heard heavy gunfire.

Hezbollah is pulling its forces from the outskirts of the Syrian capital Damascus and the Homs area, a source close to the Lebanese group said Sunday, as their ally President Bashar al-Assad faces a rebel offensive.

A war monitor said late Saturday that Islamist-led rebels had entered the strategic city of Homs, on the way towards Damascus where Syria's embattled government said it was setting up an impenetrable security cordon.

Iranian Foreign Minister Abbas Araghchi called for "political dialogue" between the Syrian government and opposition groups after a lightning offensive by rebel forces.

Turkey's foreign minister will meet with his Russian and Iranian counterparts in Doha on Saturday to try to find a solution to the renewed fighting in Syria and avoid chaos on its doorstep.

The three countries have been partners since 2017 in the Astana process seeking to end the civil war in Syria even if they have supported opposite sides on the battlefield.

Rebels on a lightning advance through Syria said on Saturday they have begun to encircle Damascus as government forces denied they had withdrawn from areas near the capital.

A source close to Hezbollah said Saturday that the group sent 2,000 fighters to a part of Syria near the border with Lebanon, as ally Damascus reels from a rebel offensive that has seized major cities in recent days.

Syrian rebel commander Hassan Abdel Ghani sought to reassure religious minorities on Saturday after Islamist-led fighters snatched key cities and swathes of territory from government control.