Five law-enforcement officials were killed and seven others wounded on Thursday by an explosive device planted by "armed terrorist group" at the southern entrance of the northern province of Idlib, state-run SANA news agency reported.

Another three explosive devices were dismantled by engineering units at Jasr al-Shoughour area in Idlib, said SANA.

Also in Idlib, seven Syrians who were kidnapped by "armed terrorists groups" were set free on Thursday by specialized authorities in a "qualitative operation" in the Maaret al-Numan city.

SANA said two terrorists were killed and 12 others were wounded during the release operation.

A day earlier, border guards foiled an attempt by an armed group to sneak into Syria via Turkish territories near al-Nasra area in Idlib suburb. A number of the group members were killed or wounded while some others ran away into Turkey, according to SANA.

The Syrian government has blamed the unrest in Syria on plots by terrorists and foreign-backed armed gangs. It said more than 2, 000 army and security personnel were killed during the 11 months, while the opposition accuses the government of attacking protesters.

The United Nation put the death toll in the Syrian unrest at around 6,000.