At least five people were killed in multiple suicide bombings early Monday in Lebanon’s eastern village of al-Qaa that lies near the border with Syria, officials said.

Four suicide blasts, at 10 minute intervals, hit the predominantly Christian village near the Customs base, the state-run National News Agency reported.

“The first attacker knocked on one of the homes in the village, but after the resident became suspicious, he blew himself up,” a military source told Agence France Presse.

“People began gathering at the site of the explosion and the three other suicide attackers blew themselves up,” he added.

“At least eight killed, including three suicide bombers, and 15 others injured,” Georges Kettaneh, the general secretary of the Lebanese Red Cross, told AFP.

Some of the wounded were in critical condition.

NNA said the attacks wounded three Lebanese soldiers stationed in the area.

Forensic experts later arrived to the scene of the blasts and launched an investigation. But it was not immediately clear what exactly the attackers were planning to target.

Al-Qaa is one of several border posts separating Lebanon and war-torn Syria. It is also home to a large number of Syrian refugees who have fled the war in Syria.

The border area has been rocked by clashes and shelling since Syria’s conflict erupted in 2011.

Lebanon’s army has fought off militants from al-Nusra Front and ISIS along the frontier and has sought to clamp down on local cells operating in the area.