An explosion ripped through a residential neighborhood in the northern Syrian city of Aleppo Sunday March 18, the country's state news agency said, calling it a "terrorist bombing," AP reported.

The report by SANA gave no information on casualties or damage. It appeared to be the second attack in two days in cities where the regime enjoys strong support.

Mohammed Saeed, an Aleppo resident, said a car bomb exploded near the Political Security Directorate in the city's central neighborhood of Suleimaniyeh. He said the neighborhood has a large Christian population.

Saeed said the explosion in Aleppo occurred around 1 p.m. (1100 GMT) and security forces started shooting in the air and cordoned off the area to prevent people from approaching. He said during that hour of the day, the area is usually crowded with people, especially on a Sunday, the first day of Syria's workweek. "It was a strong explosion. It shook parts of the city," Saeed said, citing nearby residents. "White smoke was billowing from the area."

The Britain-based Syrian Observatory for Human Rights, which relies on an activist network in Syria, also said it was a car bomb. It said dead and injured were reported but gave no numbers.

Sunday's explosion followed three suicide bombings in the capital Damascus on Saturday that killed 27 people. The government blamed them on the opposition, which it says is made up of "terrorist" groups acting out a foreign conspiracy. Some opposition leaders accused the regime of complicity in the attacks to tarnish the uprising. No group has claimed responsibility.

Both cities are considered Assad strongholds and have remained relatively insulated from the unrest shaking much of the country since the start of a popular uprising against authoritarian President Bashar Assad one year ago. The U.N. says more then 8,000 people have been killed.