Lebanese soldiers killed during border battle with Islamist militants from Syria

Isis or Jabhat al-Nusra may have been behind Friday's attack

Lebanese army troops drive armoured personnel carriers (APC) in the village of Ras Baalbak on 23 January (AFP/Getty Images)

Five Lebanese soldiers have been killed in a battle with Islamist militants near the border with Syria.

Isis has attacked Lebanon in recent months, as have fighters from al-Qaeda’s Jabhat al-Nusra, and it was unclear whether either of the groups were involved in Friday’s clash.

Both organisations are battling for supremacy in the Syrian civil war, vying to establish their own version of a Sunni so-called Islamic state.

Reports emerged last week of Isis massing up to 700 men recruited from moderate rebel groups along the border with Lebanon and making preparations to attack.

Lebanese army reinforcements arriving in nearby Arsal last year (AP)

The fighting, at a military outpost near the village of Ras Baalbek, lasted all day with Lebanese army helicopters and artillery pounding the Islamists’ positions.

“We are targeting their gatherings and positions with artillery shells and helicopter gunships. We inflicted casualties among them,” a military official said as the battle continued.

Nine militants had been killed by the time they retreated, according to a Lebanese security official.

Syrian fighters have been known to target the Lebanese army and the Shia militant group, which is based in Lebanon.

A jihadist fighter for Jabhat al-Nusra, with al-Qaeda’s emblem on his jacket (centre back), in Syria in 2013. (AFP/Getty)

In August, Jabhat al-Nusra and Isis fighters conducted a joint raid in the nearby border town of Arsal and captured some two dozen soldiers. Since then, they have murdered several of the soldiers and the rest remain captive.

The militants are demanding the release of Islamists held by the authorities in exchange for them.

Ras Baalbek also saw heavy fighting in October and residents have reportedly formed an all-Christian militia to protect themselves and the town, making an uneasy alliance with Hezbollah in the fight to keep Sunni Islamists at bay.

Lebanon is suffering the effects of the Syrian civil war, which has caused political instability and contributed to the lack of a head of state since May.

The United Nations urged the country to elect a new President as soon as possible as fighting raged on Friday, with envoy Sigrid Kaag meeting Prime Minister Tammam Salam.

“I don’t need to spell them out but they relate to the overall situation of stability, security and stabilisation of the country which is so precious to all of us, [and] the importance of finding an early mechanism to elect a president. The significance of this of course is very well understood,” Ms Kaag said, according to the Lebanese Daily Star.

Additional reporting by agencies