A security official says an explosion has occurred inside a building in south Lebanon that might have been used as a weapons depot, apparently causing some casualties.

The official says the blast occurred Monday night in the village of Tayr Filsi near the port city of Tyre. No further details were immediately available. The official spoke on condition of anonymity in line with military regulations.

A July explosion in an abandoned building in another southern village was said to have been caused by a fire in a Hezbollah arms depot. The militant group said at the time that the building housed ammunition leftover from Israeli attacks on Lebanon.