A huge explosion was heard in southern Lebanon in the village of Ain Qana, according to Lebanese broadcasters and witnesses.
The explosion occurred in an arms depot for Hezbollah in the village, one Lebanese security official in south Lebanon said, without elaborating on the cause. The official spoke on condition of anonymity in line with regulations.
An official with the militant group Hezbollah confirmed there was an explosion but declined to give further details, according to the foreign media.
Another local Hezbollah official could not confirm any casualties and said the nature of the blast was not yet clear. Both spoke on condition of anonymity because they were not authorized to give official statements.
Members of the group imposed a security cordon around the area. Security sources said earlier there were injuries in the blast.
Pictures from Lebanese news media showed clouds of dark smoke rose from the area. The cause of the blast about 50 km (30 miles) south of Beirut was not immediately clear.
Twitter account Intel Sky shared footage of what the explosion purportedly looks like. The mysterious explosion comes seven weeks after the massive explosion at Beirut port, caused by the detonation of nearly 3,000 tons of improperly stored ammonium nitrate. The explosion killed nearly 200 people, injured 6,500 and damaged tens of thousands of buildings in the capital, Beirut.
It is still not clear what caused the initial fire that ignited the chemicals, and so far no one has been held accountable.