Syrian authorities on Tuesday closed the international airport in the northern province of Aleppo, which has been surrounded by rebel forces for more than two weeks, opposition activists told Efe.

The coordinator of one opposition group in Aleppo, Mohammed Nur, said that Syrian authorities declared a 10-kilometer (6.2-mile) radius around the airport to be a "military zone" after heavy clashes with the rebels took place.

Another rebel spokesman, Abu Feras, told Efe that "the rebels managed to down a military helicopter of the Syrian regime over the airport."

Meanwhile, the so-called Local Coordination Committees reported that the Tuenan natural gas field in the northeastern province of Al Raqa had been taken over by the opposition forces.

On Dec. 30, the international mediator for Syria, Lakhdar Brahimi, warned in Cairo that some 100,000 people could die violently in Syria over the coming year, in addition to the 50,000 who have perished since March 2011 in the ongoing civil conflict, if a solution is not found. EFE