An explosion was heard Sunday in the south of the Syrian capital Damascus, with preliminary reports suggesting it was a “terrorist act”, state television said.

“Explosion heard around the southern highway in Damascus area, first reports suggest a terrorist act,” the broadcaster said.

The state outlet did not provide any more details on the incident.

Syria is locked in a civil war that has killed more than 360,000 people and displaced millions since a brutal crackdown on anti-government protests in 2011 spiralled into full conflict.

With key military backing from Russia, President Bashar al-Assad’s forces have retaken large parts of Syria from rebels and jihadists, and now control almost two-thirds of the country.

The Syrian regime in May reclaimed a final scrap of territory held by the Islamic State group in southern Damascus, cementing its total control over the capital for the first time in six years.