The Syrian army started on Friday a wide-scale offensive against the radical rebels, who have recently stormed the Damascus' suburb of Adra al-Umalyieh, a military source was cited by Syria's mainstream media as saying.

The large-scale military operation aims at dislodging the al- Qaida-linked Nusra Front fighters from Adra, a couple of days after the fighters stormed the town, killing tens of people, including state servants, and burning houses in that area.

The Nusra has also slaughtered people from the Alawite minority in Adra and placed their heads in the most popular market in the town.

"Unites of our military forces have started storming the rebels ' positions in Adra," the Syrian military source said, stressing the army's determination to "amputate the sinful hand of terrorism. "

The source added that "the criminals and those who support them will pay a steep price for the crimes they are committing against our people."

Al-Qaida-linked groups such as the Nusra Front and the Islamic State of the Iraq and the Levant have taken advantage of the anti- government movement in Syria, emerging as a serious force among the rebel groups.

The radical rebels stormed Adra following their defeat in three major towns in the rugged al-Qalamoun region north of Damascus, namely al-Nabek, Deir Attieh, and Qara.