BEIRUT (AFP) — Three people were injured when clashes erupted in the Lebanese capital late on Saturday between supporters of rival political factions, a security official said.

"They are throwing stones at each other and the army has been deployed to contain the violence," the official told AFP, adding that the confrontations were taking place near central Beirut.

"The army intervened and fired into the air to separate the two sides," he said, adding that three people were injured.

Lebanese television reported that four Molotov cocktails were thrown at a Hezbollah office in Beirut.

Similar clashes in recent days between supporters of the Western-backed government and the Shiite-led opposition have raised tensions in a country already embroiled in its worst political crisis since the 1975-1990 civil war.

The security official had said the fighting involved supporters of ruling majority leader Saad Hariri and rivals in the opposition Shiite movement Amal.

But an Amal spokesman told AFP: "Amal denies that any of its supporters were involved in the violence tonight."

Tensions have been running high in Lebanon as the country grapples with a protracted political crisis that has left it without a head of state since the end of November.

On Thursday, mass rallies were staged by rival pro- and anti-Syrian factions in Beirut, further ratcheting up the tensions.

Supporters of the Western-backed government had massed to commemorate the third anniversary of the assassination of ex-premier Rafiq Hariri while thousands gathered just a few miles away for the funeral of Imad Mughnieh, one of Hezbollah's top commanders killed in a car bombing in Syria.