The Syrian troops on Friday pounded rebel positions in several areas in the northern countryside of the capital Damascus and eliminated many fighters of radical rebel groups in the southern region, local media and activists reported.

The Syrian government troops bombarded the villages of Deir Makren and Efra in the Wadi Barada area in countryside of Damascus in southern Syria, as the Syrian air force dropped crude barrel bombs against the barren terrain of the western part of the rugged al-Qalamoun region northwest of Damascus, bordering Lebanese, according to the oppositional Syrian Observatory for Human Rights.

The shelling was coupled with clashes between the government troops and extremist groups, mainly the al-Qaida-linked Nusra Front, in the town of Ras al-Ma'ara in al-Qalamoun, according to the UK-based watchdog group, which relies on a network of activists on ground.

Syrian government troops have been engaged in battles against rebel groups and extremists since last year in the western part of al-Qalamoun, a rugged region between the central province of Homs and Damascus.

The Syrian troops managed to sever the rebels' main supply line from neighboring Lebanon during the battles that lasted from last year's winter till the spring of 2014.

However, an array of militant groups are reportedly assembling in the eastern part of al-Qalamoun to fight both government troops and the Islamic State (IS) militants.

Meanwhile, the state news agency SANA said the Syrian army eliminated many "terrorists" in the countryside of the southern provinces of Daraa and al-Qunaitera.

Leaders of the Nusra Front were among those killed, said SANA, citing military sources as saying that many of the Nusra fighters were killed in the town of Sheikh Miskin, some 22 km north of Daraa.

The Syrian government forces also killed a number of rebels between the towns of Ajami and Tal Shehab, some 17 km from the city center of Daraa and few meters away from the Jordanian borders.

Over 190,000 people have been killed and millions of others displaced inside and outside the country as a result of the Syria crisis, which has become more complicated when radical groups capitalized on the chaotic situation to achieve territorial gains.