Baalbek, Beirut: Lebanese Shiite group Hezbollah clashed with hundreds of Islamist insurgents trying to capture land in a mountainous area near the border with Syria on Sunday and both sides suffered casualties, security sources said

Gunmen crossed from Syria into eastern Lebanon and attacked Hezbollah posts, sparking fierce clashes, a Hezbollah source said.

“Hezbollah posts in the mountains around Nabi Sbat, east of Baalbek, were attacked by armed groups who came from Qalamun” in Syria, the source said.

“Hezbollah returned fire, inflicting heavy losses among the attackers.”

Residents from Nabi Sbat who fled the fighting said they saw Hezbollah convoys picking up several wounded fighters from the group during the clashes.

Hezbollah maintains several military posts along inaccessible parts of the border with Syria, and it rarely gives official details on clashes with Islamist militants or other fighters.

The fighting could be heard in the city of Baalbek, several kilometres away.

The attack comes two months after militants from Daesh and Al Qaida’s Syrian affiliate Al Nusra Front attacked Lebanese security forces in Arsal, which also lies on the Syrian border in eastern Lebanon.

The militants withdrew into the mountains around Arsal after a ceasefire, but took with them around 30 soldiers and policemen as hostages.

Three of them have since been executed, contributing to rising anxiety in Lebanon over the encroachment of militants and spillover from the war in neighbouring Syria.

Hezbollah has dispatched fighters to bolster President Bashar Al Assad’s troops against an uprising that many of Lebanon’s Sunnis support.

The conflict has exacerbated existing tensions in Lebanon, and made Hezbollah and strongholds of its support a target for extremists who have detonated bombs in several areas of Lebanon.