BEIRUT - Lebanon's third-largest city of Sidon was turned into a battle zone Monday as the military fought heavily armed followers of an extremist Sunni Muslim cleric holed up in a mosque.
Residents of the southern port fled machine-gun fire and grenade explosions that shook the coastal area.
Official reports said at least 16 soldiers were killed and 50 were wounded in two days of clashes with armed followers of Ahmad al-Assir, a maverick Sunni sheik who supports the rebels seeking to topple Syrian President Bashar Assad and whose rise is a sign of the frustration among Lebanese who resent the ascendancy of Shiites to power, led by the militant group Hezbollah.
The fierce battle that al-Assir's fighters were putting up showed how aggressive Sunni extremists have grown in Lebanon, building on anger against Syria's regime and its allies in Hezbollah.
Snipers allied with al-Assir took over rooftops, terrorizing civilians, and many were asking to be evacuated from the heavily populated neighborhood around the Bilal bin Rabbah Mosque, where al-Assir preaches.
The military appealed to the gunmen to turn themselves in. By evening, the army had stormed the mosque complex, though not the mosque itself.
In addition to the more than 20 followers of the cleric who were killed, dozens of them were arrested, officials said. It was unclear if al-Assir was in the mosque or had managed to escape.
The scenes of soldiers aiming at gunmen holed up in residential buildings and armored personnel vehicles deployed in the streets evoked memories of Lebanon's 1975-90 civil war.
The challenges facing the Lebanese military resemble those that prevailed in that conflict, which eventually splintered the army along sectarian lines.
Syria's civil war has been bleeding into Lebanon for the past year, following similar sectarian lines of Sunni and Shiite camps. Overstretched and outgunned by militias, the military has struggled on multiple fronts in the eastern Bekaa Valley and the northern city of Tripoli as armed factions fought street battles that often lasted several days.
In many cases, soldiers stood by helplessly and watched the violence.
On Monday, however, the army moved against al-Assir after his followers opened fire on an army checkpoint unprovoked.
Al-Assir, a 45-year-old bearded cleric, was relatively unknown until he began agitating last year for Hezbollah to disarm. He set up a protest tent city that closed a main road in Sidon for a month in a sit-in meant to pressure Hezbollah to disarm.