Syrian war jets hit several rebel targets in mountains on the Lebanese border where members of ISIS, also known as the Islamic State, are thought to be hiding, activists said Monday
The airstrikes hit the town of Arsal where hundreds of Syrian rebels are believed to be living in secret. The Lebanese army closed the main roads that lead to the town. Several people were killed and others wounded in Monday's attacks, Al Jazeera reported
This is not the first time the town of Arsal, a Sunni Muslim community sheltering thousands of refugees from Syria, has experienced intense clashes. The Lebanese army and rebels living in the town have fought several times before. 
Last month intense fighting broke out during a Lebanese military campaign to locate fighters loyal to Al Nusra, the al Qaeda affiliate in Syria, and ISIS. The Lebanese military arrested several suspected militants, including Jabhat al-Nusra leader Emad Jumaa. In retaliation, the rebels attacked several military checkpoints and police stations. The fighting in Arsal, then called the Battle for Arsal, set off a new campaign by the Lebanese military to crack down on extremist activity within its borders.

"What happened today is the most dangerous incident Lebanon and the Lebanese have ever faced, because it's made clear that there is someone planning and preparing to attack Lebanon as well as planning to sabotage the Lebanese army and the residents of Arsal,” the Lebanese military said in a statement after the fighting in August. Since then, rebels have killed Lebanese soldiers taken captive during the fighting. 

The town of Arsal has for months become a hotbed of violence as extremist fighters flock to the Lebanese border to find refuge. In the past, the Syrian regime has tried to quell that insurgency by conducting air raids on border towns. In March, it conducted more than 20 airstrikes on Arsal. But the threat of al-Nusra and ISIS still exists, particularly in the mountain region surrounding the city.

Monday's strikes on Arsal come as the U.S. and its Middle Eastern and European allies try to formulate a plan to fight the Sunni militant group in Iraq and Syria. The U.S. has said its effort to fight ISIS will not include a partnership of the Syrian government.