An explosion has hit a major oil pipeline in the central Syrian city of Homs, witnesses and activists say.
A large plume of smoke was seen rising from the pipeline, which runs near farmland on the edge of the Baba Amr district – the target of bombardment by government forces for more than a week.
State media blamed “armed terrorists”, but one activist group said government fighter jets had blown up the pipeline.
Activists also said security forces had begun shelling the nearby city of Hama.
Several people had been injured by rocket and mortar fire in the districts of Arbain, Amiriya, Faraiya, Elilat, Bashura and Bab Qibli, and all telecommunications had been cut, they added.
The pipeline damaged on Wednesday morning runs from the Rumeila fields in the eastern Syriac Desert to the Homs refinery, one of two in the country, which supplies the capital Damascus and the country’s south.
A dense plume of black smoke was seen rising above the city several hours after the blast, residents told the Reuters news agency.
It is not yet clear what caused the explosion, but the state news agency, Sana, reported that an “armed terrorist group” was behind it.
One activist group, the Local Co-ordination Committees, said warplanes had flown over Baba Amr – a centre of anti-government protests – and blown up the pipeline. Others said the army had shelled it by mistake.
The pipeline has been targeted several times during the uprising against President Bashar al-Assad, which began in March.
Activists say more than 400 people have died in Homs since security forces launched an offensive on opposition-held areas on 5 February.
Meanwhile, reports from Damascus say troops from the elite Republican Guard and army’s Fourth Armoured Division – both under the command of President Assad’s brother, Maher – have stormed the suburb of Barzeh, setting up roadblocks, searching houses and making arrests.
Residents told the Reuters news agency that the soldiers were looking for opposition activists and members of the Free Syrian Army, a group of army defectors who are seeking to overthrow the president by force.