A "huge explosion" near a military intelligence office in Damascus Sunday left a number of dead and wounded, according to the Syrian Observatory for Human Rights, a UK-based war
monitoring group.
State TV said early reports suggested it was a "terrorist act".
"The explosion took place near a security branch in the south of the city. There are some people killed and injured but we could not verify the toll immediately," the Observatory told AFP.
Syrian state television earlier reported that a blast had been heard around the southern highway in Damascus.
"First reports suggest a terrorist act," the broadcaster said.
Observatory chief Rami Abdel Rahman said that Sunday's blast appeared to be the first attack in Damascus in over a year.
The Syrian regime in May reclaimed a final scrap of territory held by ISIS in southern Damascus, cementing its total control over the capital for the first time in six years.
Also on Sunday, a bomb in the northwest Syrian town of Afrin killed three civilians and wounded about 20 on a public bus, several witnesses told Reuters on Sunday.
No group has claimed responsibility for the attack.
