Syrian President Bashar al-Assad's rule has ended, the country's army command announced early Sunday, with Syrian prime minister expressing readiness to hand over the government to the opposition forces who ousted Assad in a lightning offensive.

Syrian Prime Minister Mohammed Ghazi Jalali said he would not leave Syria and was ready to hand over power to the rebels.

"We are ready to cooperate with whoever the people choose," he said in a pre-recorded video from his home, shortly after rebels entered Damascus and announced that the capital was "now free of Assad".

The head of the Syrian Observatory for Human Rights, a UK-based opposition war monitor, said early Sunday that Assad left the country for an undisclosed location.

Syria's army command told officers that Assad's rule has ended, according to Reuters.

Thousands of Syrian people congregated at a main square in Damascus in cars and on foot, waving and chanting "Freedom" from the 50-year Assad family rule.

"We celebrate with the Syrian people the news of freeing our prisoners and releasing their chains and announcing the end of the era of injustice in Sednaya prison," the rebels said.

The Syrian government had detained thousands of people in Sednaya, a large military prison on the outskirts Damascus.

"All Syrians are saying that liberating Sednaya's prison is more significant than destroying Berlin's wall. Years of fear, torture, death, and subjugation will end tonight," one user wrote on X hours before the end of Assad's rule.