BEIRUT (AP) -- Syrian state television says an accidental explosion at a military depot outside the northwestern coastal city of Latakia has left six people lightly injured.

It says a "technical error" caused the Wednesday explosion at a military corps of engineers unit. The Britain-based Syrian Observatory for Human Rights, which relies on a number of activists on the ground, said at least 13 soldiers were injured.

The Observatory said smoke was rising from the depot, on the southern edge of the city. Latakia activists on Facebook also reported the arrival of ambulances and helicopters after the explosion.

Latakia province is a regime stronghold, where the population is predominantly members of President Bashar Assad's Alawite sect.