Gunmen have killed eight Lebanese soldiers in clashes that erupted near the border with Syria after the army detained a suspected jihadist from the war-torn country, the military said Sunday.
A Lebanese army medical evacuation APC drives to the entrance of the town of Arsal in the Bekaa valley by the Syrian border on August 2, 2014
The clashes are some of the worst violence to hit the tense border area of Arsal since the beginning of the war in neighbouring Syria in 2011, with gunmen attacking Lebanese soldiers and police.
They broke out on Saturday afternoon, after the detention of a Syrian man who the army said admitted being a member of Al-Qaeda's Syrian affiliate, Al-Nusra Front.
On Sunday morning, the fighting was continuing, and the army said it had lost eight soldiers.
"Army units continued military operations in the Arsal area and its surroundings throughout the night and into the morning, pursuing and engaging armed groups," the military said.
"During the battles the army lost eight martyrs and a number of others have been wounded," it said in a statement.
Throughout the night, the army said, troops battled gunmen who fired mortar shells at Arsal and the surrounding region.
The clashes began when soldiers arrested Imad Ahmed Jumaa, a Syrian man accused of belonging to Al-Nusra Front.
Gunmen angered by the arrest surrounded Lebanese army checkpoints before opening fire on troops and storming a police post in the town of Arsal, security sources said.
Two civilians were reported killed in the storming of the police post, and the gunmen were said to have taken hostage a number of policemen, though there was no immediate confirmation.
Earlier, the army said two soldiers had been briefly held by the gunmen, before troops were able to free them.
- 'Decisive and firm' response -
The army warned of the seriousness of the situation and insisted it would "not allow any party to transfer the battle from Syria to its territory (Lebanon)."
"The army will be decisive and firm in its response and will not remain silent as foreigners try to turn our land into a field for crime and terrorism, murder and kidnapping."
The outbreak of violence caused tensions in the northern city of Tripoli, where Sunni militants who back the Syrian uprising have regularly fought Lebanese security forces and residents from the Alawite sect who back Syria's President Bashar al-Assad.
A security source said two soldiers were wounded in the clashes in Tripoli which involved gunfire, rocket-propelled grenades and homemade explosive devices.
The violence in Arsal prompted domestic and international concern, with the US State Department urging all parties to respect Lebanon's policy of "dissociation" from the Syrian conflict.
The United States "strongly condemns the attack," spokeswoman Jen Psaki said, vowing "strong support" from Washington for Lebanon's state institutions.
Lebanese Prime Minister Tammam Salam condemned the Arsal assault as a "flagrant attack on the Lebanese state and the Lebanese armed forces."
He called on "all political forces to exercise wisdom and responsibility and to make every effort to protect Lebanon and distance it from the dangers around it."
The army has deployed additional forces, including two helicopters, to the region to deal with the outbreak of violence.
Arsal, which is hosting tens of thousands of Syrian refugees, has frequently been the scene of conflict with Lebanese security forces.
Syria's army has also launched regular air raids and shelled the area around Arsal, saying it is targeting rebels who have holed up in the mountainous region surrounding the border town.
- Influx of refugees -
Tensions skyrocketed there earlier this year with a major influx of refugees and fighters after Syrian forces backed by members of the allied Lebanese Shiite Hezbollah movement recaptured most of the Qalamun region, just across the border.
Despite the regime's recapture of most of Qalamun, pockets of opposition forces, including jihadists from Al-Nusra and the Islamic State group remain in the area.
Jihadists engaged in fierce clashes with the regime in the Qalamun region on Friday night, with at least 50 fighters killed, according to a Britain-based monitor.
More than 170,000 people have been killed since Syria's conflict began in March 2011, and the violence has regularly spilled into neighbouring Lebanon, which is hosting more than a million Syrian refugees.