Syrian rebels said they had attacked another military airport on Saturday and claimed to have captured more surface-to-air missiles, as the new UN-Arab League envoy formally began his mission to help end the 18-month conflict in the country.
The opposition Syrian observatory for Human Rights said a total of 56 people were killed across Syria. Most of the casualties occurred in the outskirts of Damascus and in the eastern province of Deir al-Zour.
In their attack on the military airport in Kouriss, in the northern province of Aleppo, rebels claimed to have destroyed three jets. Two other airports were attacked in recent days in the province of Idlib.
State-run Syrian media, meanwhile, said government forces had launched a counter-attack against unspecified "terrorists" in the al-Kalsa area, in the outskirts of Aleppo, and around military bases.
"Our forces have so far inflicted heavy losses among the ranks of the terrorists," SANA news agency reported.
Activist Bassam al-Halabi told dpa that the area, which includes several military bases, continued to be heavily shelled by government forces.
Inside the capital, a group of "terrorists" detonated a bomb which had been planted under the car of Brigadier Doctor Taher Sobeira, instantly killing him, SANA reported.
The Observatory said government bombardment targeted Damascus' southern neighborhood of Tadamon after street battles with rebels.
Opposition fighters have resorted to hit-and-run tactics in Damascus areas where they enjoy popular support.
Video footage posted online showed rebels in the east capturing Cobra ground-to-air missiles in a military air base in the Abu Kamal region, near the Iraqi-Syrian border. Rebels claimed to have captured 50 soldiers in the base after killing their commander.
Rami Abdul-Rahman, the head of the observatory, described the attack on the Hamdan base in Deir al-Zour as a "major tactical step by the rebels."
News out of Syria cannot be independently verified as the government bans journalists from entering restive areas.
Meanwhile, Deputy Foreign Minister Faisal Mikdad lashed out at Turkey in an interview with Iran's Arabic-language al-Alam TV.
"Turkey nowadays trains and allows in terrorists, allows in al-Qaeda. Most of the terrorists in Syria come from Turkey."
His comments came as Turkish Prime Minister Recep Tayyip Erdogan urged the UN Security Council to approve a resolution allowing for the creation of a buffer-zone to protect refugees inside Syria.
Syrian-Turkish relations have deteriorated since the conflict in Syria began last year, with Turkey now hosting some 80,000 refugees.
Meanwhile, Algerian diplomat Lakhdar Brahimi formally began his mission, after his predecessor, Kofi Annan, stepped down.
Brahimi plans to visit Syria within the coming few weeks and hold talks in Cairo with Arab League officials.
In Moscow, Russian Foreign Minister Sergei Lavrov labeled as unrealistic demands that Syrian President Bashar Assad step down as a precondition for settling the crisis.
"No matter what your attitude toward the Syrian regime is, saying that, while battles are under way in cities, the only solution is unilateral capitulation of one of the fighting forces is absolutely unrealistic," Lavrov said in a lecture for students of the Moscow State Institute of International Relations.
"It is not about ideology. We are not backing any regime or any individuals in the Syrian situation. We just proceed from what is realistic," he said, in comments carried by Interfax news agency.
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