A suicide bomber killed two Lebanese soldiers and a civilian with a car bomb at an army checkpoint in a Hezbollah stronghold in northeast Lebanon on Saturday, security sources said.

The Nusra Front in Lebanon – a militant Sunni group named after one of the factions fighting against President Bashar al-Assad in Syria – said it carried out the attack, in a statement posted on Twitter and a website used by militant groups.

Hezbollah, an Iranian-backed political and military movement, is fighting alongside Assad’s forces against predominantly Sunni Muslim rebels in a conflict that has exacerbated sectarian tensions in Lebanon.