The Syrian government appeared to have fallen on Sunday in a stunning end to the 50-year rule of the Assad family after a lightning rebel offensive.

The head of a Syrian opposition war monitor said President Bashar al-Assad had left the country for an undisclosed location, fleeing ahead of insurgents who said they had entered Damascus after a stunning advance across the country.

Syrian Prime Minister Mohammed Ghazi Jalali said the government was ready to “extend its hand” to the opposition and hand over its functions to a transitional government.

“I am in my house and I have not left, and this is because of my belonging to this country,” Jalili said in a video statement. He said he would go to his office to continue work in the morning and called on Syrian citizens not to deface public property.

He did not address reports that Assad had left the country.

Rami Abdurrahman of the Syrian Observatory for Human Rights said that Assad took a flight on Sunday from Damascus.