The headquarters of the ruling Baath Party was set on fire in the Syrian city of Deraa as thousands demanded an end to 48 years of emergency law.

The demonstrators also set ablaze the main courts complex and two phone company branches.

One of the firms, Syriatel, is owned by President Bashar al-Assad's cousin Rami Makhlouf.

‘They burned the symbols of oppression and corruption,’ an activist said. ‘The banks nearby were not touched.’

President Assad is facing the biggest challenge to his rule since he succeeded his late father, Hafez al-Assad, 11 years ago.

He has sent government officials to try to placate Deraa but thousands rallied for a third day.

‘No, no to emergency law. We are a people infatuated with freedom,’ marchers chanted, despite the arrival in Deraa of a government delegation to pay condolences to relatives of victims killed by security forces in demonstrations there this week.

Security forces fired tear gas at the protesters. Around 40 people were taken to be treated for gas inhalation at the main Omari mosque in the old city, residents said.

Syria has been under emergency law since the Baath Party took power 1963 and banned all opposition.

The protesters were in control of the old quarters of Deraa by nightfall, with heavy security presence in the rest of the city, which is near the border with Jordan.