Beirut: A bombing in the Syrian capital on Sunday targeted a military checkpoint on a main highway during rush hour, state media reported.

There was no immediate word on casualties from the blast in the southern neighborhood of Qazaz, near the highway leading into central Damascus. State TV gave few details about the explosion, which happened on the first working day of the week, but said it appeared to have been "a terrorist act."

State news agency SANA said the blast targeted a military checkpoint in the area, adding that nearby roads were closed. It added that a second attack in the same area was thwarted by security forces.

The Britain-based Syrian Observatory for Human Rights said the blast targeted a military intelligence department.  Left a number of dead and wounded, a war monitor said, after state TV said early reports suggested 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 Britain-based Syrian Observatory for Human Rights told AFP.

Attacks have been rare in Damascus since Syrian government forces captured the last rebel-held neighborhoods and suburbs of the capital last year.

The head of the city's civil defence, Asef Hababe, told Reuters the blast came from military technicians detonating a bomb.

Bombings had left hundreds dead over the course of the nearly eight-year civil war.

It was unclear if the blast was caused by a bomb that was planted or a suicide attack, the monitor said, adding that shooting followed the explosion.