Updated 8pm - Death toll rises

A car bomb in Damascus killed 20 people today and wounded dozens more, the Syrian Foreign Ministry said in a letter to the U.N. secretary-general and the chair of the UN Security Council, the state news agency SANA reported.

The blast was caused by a suicide attacker who blew himself up after being surrounded by security forces in the Bab Touma district of the capital. Syrian officials said it was one of three car bombs militants had meant to set off in crowded parts of the city on Sunday. Security forces pursued and destroyed the other two.

State media said security forces intercepted the two other car bombs, suggesting they were controlled explosions.

Footage on state TV from the scene of one explosion, along the road to the airport, shows at least two scorched vehicles. The closed-off street is littered with debris, while security forces roam the area.

State TV said security forces detected two car bombs at an entrance to the city, and they foiled a plot to target crowded areas on the first day of work after the long Muslim holiday that follows Ramadan.

Such attacks have been relatively rare in Damascus, the seat of power for president Bashar Assad. Pro-government forces have been fighting to drive rebels from Ain Terma, one of their last strongholds on the eastern outskirts of Damascus.