Updated

A senior Lebanese military official says clashes have erupted outside the Iranian embassy in the capital between protesters opposing Hezbollah's participation in the Syrian war and unidentified locals, killing one demonstrator.

The official identified the man killed as a 28-year-old from the small Lebanese Option Party which had called for the Sunday anti-Hezbollah protest. He spoke on condition of anonymity in line with regulations.

The protest at the embassy coincided with another small rally in downtown Beirut also criticizing Hezbollah's military intervention in Syria's conflict.

Hezbollah's overt participation in the fighting in Syria has increasingly heightened political and sectarian tensions in Lebanon. Clashes in north Lebanon have intensified since Hezbollah said last month it would side with Syria's President Bashar Assad until he defeats the rebels who seek his removal.