BEIRUT — A deadly confrontation worsened Monday between Lebanese forces and Islamist insurgents from Syria who seized the border town of Arsal over the weekend, in the most serious spillover of the Syrian civil war into Lebanese territory since the conflict began more than three years ago.
The Lebanese army said it was engaged in fierce battles with the Islamists in Arsal, where witnesses reached by telephone, including the deputy mayor, said shelling had hit the town from multiple directions and many residents had fled.
Thousands of Lebanese civilians and Syrian war refugees fled the area Monday, the Associated Press reported. It said 17 Lebanese soldiers had been killed in three days of fighting.
Arsal is the temporary home of many Syrians seeking sanctuary from the fighting in their home country. A predominantly Sunni Muslim town, it has a population of 40,000, but that number has almost tripled because of the presence of Syrian refugees and rebels.
“The situation is miserable,” said Arsal’s deputy mayor, Ahmad Flitti. “Now the shelters are full, soon we are going to have shortages in drugs, and hospitals here will not be able to receive more wounded.”
The Lebanese army said 86 of its soldiers were wounded and 22 missing. More than 20 Islamist fighters were also believed to have been killed.
The Arsal fighting began on Friday when the Lebanese army arrested Imad Ahmad Jomaa, the commander of a Syrian Islamist rebel group there.
His disciples, which included brigades affiliated with Al Qaeda and the Islamic State, responded by attacking Lebanese troops and quickly seized control of the town. They have demanded Jomaa’s release as a condition for any cease-fire.
“Let them release our emir and we are ready to pull out from all over the town,” said a Jomaa deputy, reached by phone in Arsal, “or else we will escalate and expand, and we will ask for more demands.”
Cross-border clashes and shelling from the Syrian side have occasionally disrupted the Syria-Lebanon frontier, but the takeover of a town in Lebanon by members of the Islamic State had not happened before.
“It’s another front for ISIS and another sign containment of the Syria crisis has failed,” said Andrew J. Tabler, a senior fellow at the Washington Institute for Near East Policy, using another acronym for the group.
The Lebanese Cabinet met in an emergency session Monday to deal with the Arsal crisis, and Prime Minister Tammam Salam appeared to rule out negotiations, even if the occupiers are holding soldiers as captives.
“There is no political solution with extremist groups who are manipulating the Arab communities under religious obscurantism and strange titles, seeking to transfer their sick acts into Lebanon,” Salam said in a televised statement. “The only solution is the withdrawal of the gunmen from Arsal and its surroundings.”