Syrian state television says a mortar shell landed near a hospital in a government-controlled neighborhood of the central city of Homs, killing at least five people.
State TV says the mortar round hit a car near the Al-Malek Hospital in the Akrama neighborhood. It says 13 people were also wounded in Thursday's attack.
The Britain-based Syrian Observatory for Human Rights put the death toll at three, but said it isn't clear whether the explosion was caused by a car bomb or a mortar shell.
Akrama is predominantly home to members of President Bashar Assad's Alawite sect.
Syria's opposition is dominated by the country's Sunni Muslim majority.
Both the government and the rebels frequently shell civilian areas of the opposing side, although Assad's forces have far greater firepower at their disposal.