BEIRUT, July 21 (Xinhua) -- Lebanon's Hezbollah militant group said on Friday that its fighters had begun an operation against militants on both sides of the country's border with Syria.
Hezbollah's al-Manar television and its "War Media" social media channels carried announcements of "the start of a military operation to purge outskirts of Arsal and Qalamoun of armed terrorists."
The operation has been anticipated for several weeks, and comes after Lebanese soldiers carrying out raids on Syrian refugee camps in the area were met with suicide bombings and a grenade attack.
Military sources told Xinhua on condition of anonymity that the Syrian Army and Hezbollah fighters started since dawn Friday advancing towards the areas occupied by militants on the Flita front inside the Syrian territories, and the outskirts of the border town of Arsal from the Lebanese side.
The source added that the attack was preceded by heavy artillery and rocket fire, while Syrian warplanes launched more than 41 raids in less than 12 hours on the militants' posts.
It pointed that the Hezbollah fighters crossed the demarcation line with the militants on the outskirts of Arsal and advanced towards Wadi al-Oueini and Wadi al-Zaarour while the Syrian army crossed the line and advanced towards al-Qalamoun and Flita.
Lebanon's Prime Minister Saad Hariri has said "the Lebanese army will carry out a planned-out operation in outskirts of Arsal and the government gives it freedom to do so."
There was no official indication on Friday on whether Lebanese troops were involved in the fighting in the mountainous border region.
The security situation in Arsal has long been a concern.
In 2014, militants kidnapped 30 soldiers and policemen after clashes in the area. Four of the hostages were killed and a fifth died of his wounds, while 16 were eventually released in December 2015 and another nine hostages are still being held.
Around 45,000 Syrian refugees registered with the United Nations live in the town, but more are believed to be living in camps in the outskirts area, although their numbers have not been confirmed.