Syria's army units have started a wide-scale "qualitative" operation in the northern province of Idlib, targeting hideouts of "armed terrorist groups," the private al-Watan daily reported on Sunday.

Fierce clashes erupted late on Saturday between the two sides, said the paper, noting that the armed groups have planted explosive devices of different sizes in many streets and public squares in the city.

Quoting an official source, the paper said the crackdown is moving to restore normalcy to the city, assuring no casualties were caused among the army.

The paper said the government has launched similar crackdown in other cities near Idlib, adding that tens of wanted criminals were arrested.

Private Sham FM radio said the army troops killed 14 of the gunmen during the operation in Idlib.

On the other hand, the Britain-based pro-opposition Syrian Observatory for Human Rights said 16 rebel fighters, seven soldiers and four civilians were killed in the Idlib fighting, and that another 15 people, including three soldiers, were killed in violence elsewhere.

Meanwhile, an "armed terrorist group" assassinated on Saturday a Colonel in Ashrafiyyet Sahnaya, a Damascus suburb, the state-run SANA said.

It indicated that the armed group shot Colonel Nidal Sakkr when he was heading to a military unit, killing him on the spot.

Separately, SANA said Syrian authorities on Saturday clashed with "terrorist" in al-Hrak al-Sharqi area in a suburb of the southern province of Daraa, killing and arresting several " terrorists."

The authorities seized their weapons, included some RPG rounds, 12 shotguns, 9 military pistols, ammunition and advanced communication devices. A pick-up truck with large amounts of explosives and a car loaded with vests were also confiscated.

The Syrian government has accused some Arab and Western countries of providing weapons and financial support to the armed groups. It said in December 2011 that "armed terrorist groups" had killed more than 2,000 army and security personnel during the unrest. The United Nations said recently that over 7,500 people have died in Syria's violence.