A group of suicide bombers detonated their explosives in a northeastern Lebanese village near the border with Syria on Monday, killing five people and wounding at least 15, a Lebanese military official and paramedics said.

The National News Agency said the blasts occurred in the predominantly Christian village of Qaa, only few hundred yards away from the border. It said four suicide bombers were involved in the rare multiple attack.

No group immediately claimed responsibility for the attack.

The villagers became suspicious of the men as they were passing through the village around 4 am local time, an eyewitness in Qaa said. When civilian security men who guard the village called out to them, they threw a hand grenade before successively blowing themselves up among civilians.

A Lebanese military official, who spoke on condition of anonymity in line with regulations, said one suicide attacker blew himself up in front of one of the homes, while three other attackers followed, detonating their suicide vests one after the other as people gathered in the area.

Four members of the military were among the wounded, the official added. An investigation is underway.

Qaa’s mayor, Bashir Matar, described in an interview with the Beirut-based pan Arab channel Al-Mayadeen how the fourth attacker was gunned down.

Matar said it was unclear what had trigged the first explosion but once people started gathering, another explosion occurred followed by a third one.