Thousands of people are fleeing Lebanon’s eastern border town of Arsal, as the Lebanese army and rebels from Syria clash for a third day.

The fighting began on Saturday, when rebels raided the town after Lebanese forces detained an alleged member of the Syrian Islamist militant group al-Nusra Front.

At least 13 Lebanese soldiers have been killed since Saturday.

The area is known for regular tension between the army and Syrian militias.

Residents said they made use of a relative lull to pack up and leave.

Black smoke could be seen billowing over the mainly Sunni town, and the noise of heavy gunfire and shelling could be heard from a distance as tanks pounded rebel positions.

Syrian refugees were also among those fleeing.

On Saturday, the Syrian fighters briefly captured a police station in the town, which is home to thousands of refugees from the war in Syria.

An al-Nusra Front spokesman told Reuters news agency they were demanding the release of a leader, Emad Jumaa, after he was arrested at a checkpoint near the town.

The front, an affiliate of al-Qaeda in Syria, is one of several rebel groups fighting against the Syrian government.

Lebanon – with a population of about five million – hosts more than a million Syrian refugees.