A car bomb killed several people near a security building in the residential Suleimaniyeh neighborhood in the city of Aleppo, Syria, early Sunday afternoon.

The Syrian Observatory for Human Rights reported several deaths and many injuries in the attack. The Syrian authorities have closed roads leading to the site of the attack, according to Israel Radio.

SANA, the Syrian state news agency, has called it a “terrorist bombing.” Reports by SANA said two people were killed and 30 were wounded.

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 around 1 p.m. local time, 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.”

Earlier Sunday, there were reports of renewed shelling in the rebel stronghold of Homs, opposition activists said. There were no immediate reports of casualties in those attacks.

The explosion comes one day after a twin bombing attack in Damascus, which left 27 dead. The Syrian regime blamed rebels for the attack, though rebels deny the claim.

March 18 is considered by many activists the one-year anniversary of the Syrian uprising seeking to oust authoritarian President Bashar Assad, and although marches were planned around the country, a crackdown by the Syrian regime is preventing those events from taking place.

Syrian security forces and pro-government thugs swiftly dispersed an anti-regime rally in the capital Damascus and arrested opposition leaders.  Activists said the deployment of government snipers and tanks, as well as clashes between rebels and regime forces, deterred major demonstrations in some other parts of the country.

The anniversary falls after government offensives against rebel enclaves in the central city of Homs, the northern town of Idlib and the uprising’s birthplace in the city of Daraa.

The spotty turnout shows how armed confrontation has largely eclipsed the mass popular demonstrations that originally drove the uprising.

Since then, Assad’s security forces have violently sought to crush all signs of dissent, and protest and international condemnation have spread. Many in the opposition have taken up arms to defend themselves and attack government forces as the increasingly militarized conflict has become one of the bloodiest of the Arab Spring. UN reports say that more than 8,000 people have been killed.