Looking for His glorious appearing! Titus 2:13

"What happened is far more dangerous than some believe," Kahwaji told reporters in Beirut, saying the arrested commander had admitted to planning a large attack against army positions.

"The terrorist attack which occurred yesterday was not an attack by chance or coincidence. It was planned previously, a long time ago, awaiting the appropriate time," he said.

An unknown number of militants and civilians, possibly dozens, were also killed in the fighting. More than a dozen members of Lebanon's security forces were taken captive, while some 15 soldiers are also missing, security sources said.

Security officials say the gunmen in Arsal include fighters linked to the Islamic State, an al Qaeda offshoot that has seized territory in Syria and Iraq, as well as Syria's al Qaeda branch, the Nusra Front.

Bombardment of the area prompted a large number of the tens of thousands of refugees sheltering in the area to flee, residents said. Entire refugee families abandoned their shelters as fires broke out in the camps, Syrian activists in the area said. Television images showed plumes of black smoke rising from the mountainous area around the town.

"They're shelling from all directions," said Qassem Al-Zein, a Syrian doctor at the field hospital in Arsal, adding that the hospital had recorded 17 civilians killed so far, including refugees hit by the shelling. The wounded numbered 150, up to 15 of whom were militants, he said.