BEIRUT -- Lebanese army units battled followers of a hard-line Sunni cleric holed up in a mosque complex in a southern port city on Monday, the second day of fighting that has left at least 16 soldiers dead, the military said.
The clashes in Sidon, Lebanon's third-largest city some 40 kilometers (25 miles) south of Beirut, are the latest bout of violence in Lebanon linked to the conflict in neighboring Syria.
They are the bloodiest yet involving the army -- at least two of those killed are officers. The Lebanese media has depicted the clashes as a test for the state in containing armed groups that have taken up the cause of the warring sides in Syria, whose sectarian makeup mirrors that of its smaller neighbor.
The two days of fighting between troops and armed supporters of Sheikh Ahmad al-Assir have transformed the city, which had been largely spared the violence plaguing border areas near Syria, into a combat zone.
The National News Agency said the clashes also left fifty wounded. Hospital officials said at least three of al-Assir's supporters died in the fighting.
The military in a statement said the gunmen were using the religious compound to fire on its troops and had taken civilians as shields.
Machine-gun fire and rocket-propelled grenade explosions caused panic among residents of Sidon. Residents reported power and water outage.
The city streets appeared largely deserted Monday. Local media reported many residents were asking for evacuation from the heavily populated neighborhood around the Bilal bin Rabbah Mosque where al-Assir preaches, and where the fighting has been concentrated. The local municipality said that the city is "a war zone," appealing for a cease-fire to evacuate the civilians and wounded in the area.
Many people living on upper floors came down or fled to safer areas, while others were seen running away from fighting areas carrying children. Others remained locked up in their homes or shops, fearing getting caught in the crossfire. Gray smoke billowed over parts of the city.
The military appealed to the gunmen to hand themselves in. In its statement, it said that it "reassures all Lebanese that it will continue to uproot the strife and will not stop its operations until security is totally restored to the city and its boroughs, and falls under the rule of law and order."
The clashes erupted Sunday in the predominantly Sunni city after troops arrested a follower of al-Assir. The army says supporters of the cleric opened fire without provocation on an army checkpoint.
Al-Assir is a virulent critic of the powerful Shiite militant Hezbollah group, which along with its allies dominates Lebanon's government. He supports rebels fighting to oust Syria's President Bashar Assad.
A few Hezbollah supporters in the city were briefly drawn into the fight Sunday, firing on al-Assir's supporters. At least one was killed, according to his relatives in the city who spoke anonymously out of concerns for their security.
But the group appeared to be staying largely out of the ongoing clashes. Last week, al-Assir supporters fought with pro-Hezbollah gunmen, leaving two killed.
Early Monday, al-Assir appealed to his supporters through his Twitter account in other parts of Lebanon to rise to his help, threatening to widen the scale of clashes.
The tweets did not give a clear statement on how the battle began. It came after a series of incidents pitting the cleric's followers against other groups in the town, including Hezbollah supporters and the army.
The cleric is believed to have hundreds of armed supporters in Sidon involved in the fighting. Dozens of al-Assir's gunmen also partially shut down the main highway linking south Lebanon with Beirut. On Monday, they opened fire in other parts of the city, with local media reporting gunshots in the city's market.
Fighting also broke out in parts of Ein el-Hilweh, a teeming Palestinian refugee camp near Sidon, where al-Assir has supporters. Islamist factions inside the camp lobbed mortars at military checkpoints around the camp. Tension also spread to the north in Tripoli, Lebanon's second largest city. Masked gunmen roamed the city center, firing in the air and forcing shops and businesses to shut down in solidarity with al-Assir. Dozens of gunmen also set fire to tires, blocking roads. The city's main streets were emptying out. There was no unusual military or security deployment.
Sectarian clashes in Lebanon tied to the Syrian conflict have intensified in recent weeks, especially after Hezbollah sent fighters to support Assad's forces. Most of the rebels fighting to topple Assad are from Syria's Sunni majority, while the President Bashar Assad belongs to the Alawite sect, an offshoot of Shiite Islam.
Walid al-Moallem, Syria's foreign minister, blamed the violence in Lebanon on the international decision to arm rebels, saying that it will only serve to prolong the fighting in Syria and will impact neighboring Lebanon.
"What is going in Sidon is very dangerous, very dangerous," he told reporters in Damascus. "We warned since the start that the impact of what happens in Syria on neighboring countries will be grave."
In Syria, activists reported fighting Monday between Syrian troops and rebels in the northern province of Aleppo as well as districts on the edge of the Syrian capital and its suburbs.
Clashes in Lebanon have also mostly pitted Sunni against Shiite. The most frequent outbreaks have involved rival neighborhoods in the northern port city of Tripoli, close to the Syrian border.
President Michel Suleiman called for an emergency security meeting later Monday.
Headlines of Lebanon's newspapers were all dominated by the violence in Sidon, with many seeing it as a test for the state to impose order. "An attempt to assassinate Sidon and the military," read the headline of the daily al-Safir. "Al-Assir crosses the red line," read another headline in al-Jomhouria daily. A third headline in al-Nahar read: "Yesterday war in Sidon. Today, decisiveness or settlement?"