BEIRUT (AP) - Rebels captured part of a sprawling Syrian army base outside the embattled northern city of Aleppo, tightening the opposition's grip on areas close to the Turkish border, activists said Monday.
The gains by rebel forces came as the European Union denounced the Syrian conflict, which activists say has killed more than 40,000 people.
"The current situation in Syria is a stain on the world's conscience and the international community has a moral duty to address it," European Commission president Jose Manuel Barroso said in Oslo as the EU received the Nobel Peace Prize.
The rebels also killed 13 soldiers in an ambush near a strategic northern town along a road linking Aleppo, the nation's largest city and business hub, with Damascus, and captured 20 soldiers and policemen at a major post on the highway linking the central town of Salamiyeh with the northern city of Raqqa, activists said.
Once on the defensive, Syria's rebels have gained momentum in recent weeks with a number of tactical advances, seizing airbases near Damascus and Aleppo and putting President Bashar Assad's forces on their heels.
In an interview with Dubai TV, Syria's top military defector said Assad's regime is "over" and advised the president to leave office and let the country's people decide their own fate.
Manaf Tlass, a Syrian general who was the first member of Assad's inner circle to break ranks and join the opposition, said "we are at a turning point and the train of the revolution will be victorious." Tlass, who defected in July, said he urged Assad to listen to the people's demands and implement serious reforms.
"I used to talk to the president four times a day and I used to see him every other day. I tried to convince him to react with the rebels. He always avoided answering and used to say they are armed gangs," Tlass said from Paris, where he has been spending much of his time.
"I told him tens of times, and sometimes in a loud voice that "you should be with your people' and he did not answer," Tlass said. "It's over ... I advise him to leave."
The Britain-based Syrian Observatory for Human Rights said the rebels entered the Sheik Suleiman military base outside Aleppo on Sunday afternoon, after weeks of fighting around the facility. Last month, they captured another base near the city, 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 such as Jabhat al-Nusra, Mujahedeen Shura Council and the Muhajireen group.
In the fight for the Sheik Suleiman base, as the rebels seized key sectors of the facility, which is home to the 111th Regiment, including its command center, the Observatory said.
About 140 Syrian troops fled to another, nearby base as the rebels advanced, Abdul-Rahman said, adding that opposition fighters captured seven government troops and killed two soldiers in the fighting.