At least 34 people have been killed by a car bomb in central Syria, according to Syrian state television and an activist group.

State television's report said a bomb exploded on Friday morning in the government-controlled Horrah village, which is in the countryside near the city of Hama in central Syria.

About 50 people, mostly civilians, were also injured, the report said.

The attack was described as a "terrorist" bombing, wording the government uses to refer to rebels fighting forces loyal to Syrian President Bashar al-Assad.

A separate report from the Britain-based Syrian Observatory for Human Rights put the number of dead at 37. In a statement, the anti-government group said the toll was likely to rise because many of the wounded were in critical condition.

Car bombs are common in Syria's civil war, now in its fourth year.

On Thursday evening, a car bomb exploded near a school in the pro-government Nazha district of the central city of Homs, killing three people and wounding nine, Syrian state media said.

Since it began in 2011, the conflict has killed more than 160,000 people, according to opposition activists.

Foreign fighters and Syrian rebels who have taken up al-Qaeda-style ideologies have played an increasingly powerful role among fighters, dampening the West's support for the rebellion to overthrow Assad.