Lebanese soldiers opened fire to break up a protest outside a mosque in the southern port of Sidon on Friday, days after the army fought Sunni Islamist militants there and seized control of the area.
The fighting earlier this week was the deadliest outbreak of violence in Lebanon to be fuelled by the two-year conflict in neighbouring Syria. Some 18 soldiers were killed and dozens of supporters of firebrand cleric Sheikh Ahmed al-Assir also died.
On Friday a witness at Sidon's charred and bullet-scarred Bilal bin Rabah mosque said he saw the army fire shots as a crowd of pro-Assir protesters marched towards it after finishing Friday prayers at another place of worship in the city.
The army said soldiers had fired into the air and not at the protesters.
Assir, now on the run, was a staunch supporter of Syria's Sunni-led uprising and accused the army of backing the interests of the Shi'ite Muslim group Hezbollah, which has openly entered the fighting in Syria on behalf of Assad.
Unprecedented clashes erupted between Assir's gunmen and the Lebanese army in Sidon on Sunday, reportedly after some militants attacked a group of soldiers in response to the arrest of an Assir supporter.
The violence has strained fragile sectarian relations across Lebanon and sparked fears that Syria-related clashes could eventually plunge the tiny country back into civil war, like the one that raged from 1975 to 1990.