Updated 9:27 pm: Armed supporters of Salafi Sheikh Ahmad al-Assir killed six Lebanese soldiers near the southern town of Sidon on Sunday, the army said.
"An armed group loyal to Sheikh Ahmad al-Assir attacked, for no reason, a Lebanese army checkpoint in the village of Abra" just east of Sidon, it said.
The army identified the victims as First Lieutenant Samer Geryes Tanyous, Lieutenant George Elian Bou Saab, Sergeant Ali Adnan al-Masri, and soldiers Rami Ali Baker, Bilal Ali Saleh and Elie Nicolas Rahme.
It added that one gunmen was killed and 15 injured.
The fighting erupted when Assir supporters surrounded an army checkpoint in Abra, where a vehicle transporting other supporters of the radical cleric had been stopped, a security source told AFP.
"After the armed men attacked with gunfire," the army fired back, the source added.
The army vowed it "will not tolerate" the latest developments, and that it "will continue to fulfill its mandate to suppress strife."