A car bomb has killed at least 34 people and wounded more than 50 in the flashpoint city of Hama, central Syria, according to state-run news agency and opposition groups.

Sana news agency blamed the attack on rebels fighting to overthrow president Bashar al-Assad. The explosion took place in Horrah village in the countryside near Hama, a government-controlled area.

The British-based Syrian Observatory for Human Rights said that at least 37 people were killed in the bombing but the death toll was likely to rise because many of the wounded were in critical condition.

The Islamic Front, a rebel umbrella group battling government forces, claimed responsibility for the attack, saying that the radio-controlled bomb targeted "a gathering of Assad militia".

Islamic Front target check point at al-Horra Assad loyal village in Hama with car bomb pic.twitter.com/SgxaiVjeFy — al-Gharib الغريب (@troublejee) June 20, 2014

They also released a video of the moment of the explosion from their official YouTube account. The footage cannot be independently verified.

Car bombs are common in Syria's civil war, now in its fourth year. The conflict has killed more than 160,000 people according to opposition activists. Nearly a third of the victims were civilians.

The Islamic Front was founded last year out of the merging of seven leading Islamist rebel groups: Ahrar al-Sham, Jaysh al-Islam, Suqour al-Sham, Liwa al-Tawhid, Liwa al-Haqq, Ansar al-Sham and the Kurdish Islamic Front. It said it will be an "independent political, military and social formation" to topple the Assad regime and build an Islamic state.

The Islamic Front's new leader is Ahmed Issa al-Sheikh of Suqour al-Sham. He was previously head of the Syrian Islamic Liberation Front (SILF), a coalition of Islamist factions aligned to the Supreme Military Council of the Free Syrian Army.