BEIRUT — Syrian rebels captured parts of another large army base in the country's north, just west of the city of Aleppo, tightening the opposition's grip on areas close to the Turkish border, activists said Monday.
Elsewhere, the rebels killed 13 soldiers in an ambush near a strategic northern town along a road linking Aleppo with Damascus, activists reported.
The Britain-based Syrian Observatory for Human Rights said the rebels entered the Sheik Suleiman military base on Sunday afternoon, after weeks of fighting around it.
The development was a significant boost for the rebels fighting to topple President Bashar Assad and defeat his military. Last month, they captured another base near Aleppo, the Syrian army's 46th Regiment base.
Rami Abdul-Rahman, who heads to Observatory, said the rebels who stormed Sheik Suleiman belong to hardline Islamic militant groups.
Abdul-Rahman told The Associated Press that fighters from Jabhat al-Nusra, Mujahedeen Shura Council and the Muhajireen group took part in the battle for the Sheik Suleiman base.
U.S. officials have said the Obama administration is preparing to designate the Jabhat al-Nusra group, which has alleged ties to al-Qaida, a terrorist organization.
The Observatory said the rebels seized key sectors of the base, home of 111th Regiment, including its command center.
About 140 Syrian troops fled to another, nearby base as the rebels advanced, Abdul-Rahman said, adding that rebels captured seven government troops and killed two soldiers in the fighting.
Amateur videos released by activists showed gunmen walking inside the base, carrying a militant black Islamic flag.
The footage also showed rebels driving around in a captured tank and manning heavy anti-aircraft machine guns. The activist videos appear genuine and correspond to AP's reporting on the events depicted.
Fighting around Syria has intensified in the past few months. The uprising, which began with peaceful protests against Assad's regime in March 2011, has escalated into a civil war that has killed more than 40,000 people, according to activists.
“This is what we captured from Assad's army,” a rebel says in the video, carrying an automatic rifle and a walkie-talkie and pointing to the heavy machine guns.
Abdul-Rahman said the rebels tried to storm Sheik Suleiman base two weeks ago but were pushed back by troops who killed nearly two dozen rebel fighters.
The Observatory also reported heavy fighting Monday on the southern edge of the strategic rebel-held town of Maaret al-Numan, captured from government troops in October. It said rebels ambushed an army unit, killing at least 13 soldiers.
The group said Syrian warplanes bombed the town after the death of the solders.
Mohammed Kanaan, an activist based in Maaret al-Numan said rebels stormed army positions south of the town and killed many soldiers.
“The town is witnessing some of the worst clashes in weeks,” said Kanaan via Skype.
The town is on the highway that links the capital, Damascus, with Aleppo, Syria's largest city and commercial center that has been the scene of clashes between rebels and troops since July.
Activists also reported violence in other areas, including the eastern province of Deir el-Zour, central region of Homs as well as villages and towns near Damascus International Airport south of the capital.
A resident in Damascus, speaking on condition of anonymity for fear of government reprisal, told The AP that he was hearing cracks of gunfire and explosions inside and outside the capital early Monday.