Syria's ambassador to Iraq has defected to the opposition and urged other senior Syrian politicians and members of the military to do the same.
Nawaf Fares is the first senior Syrian diplomat to abandon the government of President Bashar al-Assad since a violent uprising began 16 months ago.
He is from Deir al-Zor in eastern Syria, the scene of a ferocious onslaught by government forces.
The move comes just a week after Syrian General Manaf Tlas, from a powerful family close to Mr Assad, also defected, the BBC reports.
Mr Fares confirmed his defection in a statement broadcast on the social networking site Facebook and al-Jazeera TV.
With Syrian revolutionary flags behind him, he read out the statement saying he was resigning both as Syria's ambassador to Iraq and as a member of the ruling Baath Party.
Meanwhile, Western nations are urging the United Nations to threaten tough sanctions against Syria.
They want a 10-day sanctions ultimatum to be part of a Security Council resolution on the future of the UN's observer mission in the country.
A new resolution must be passed before the mission's mandate ends on Friday next week.