Five people were killed and 20 wounded today when rebel rocket fire hit a petrol station in a government-held part of Syria's central Homs city, state news agency SANA said.

The missile fire set fire to a tanker as it was unloading in the Inshaat neighbourhood of Homs, which is the provincial capital and largely under government control,  SANA said. 

"The rocket fire came from Talbisseh in northern Homs province where extremist groups led by (Al-Qaeda affiliate) Al-Nusra Front are located," the agency added.

The Syrian Observatory for Human Rights, a Britain-based monitor, also reported five dead in a blast at the petrol station, with 40 people injured.

But it said there was conflicting information on whether the blast was caused by a tanker exploding or rocket fire hitting the station.