Militants launched two Fidayeen attacks on the military installations in the heart of Syria’s western city of Homs killing 42 people, the Syrian Observatory for Human Rights said.
“The attacks hit the headquarters of state security and military intelligence in two central districts,” the Observatory director Rami Abdel Rahman told AFP.
The UK-based Syrian Observatory for Human Rights said that loud explosions and gunfire were heard following the assault in the western city.
However, it was not immediately clear if the militants were from Islamic State or other groups.
The attacks come on the second day of peace talks in Geneva over Syria’s six-year-old civil war that has killed hundreds of thousands of people.
Homs has been under the full control of the government since May 2014 when rebels withdrew from the city centre under a UN-brokered truce deal.
But it has witnessed repeated bombings since then. Twin attacks killed 64 people early last year.