BAGHDAD / Aswat al-Iraq: The Free Syrian Army seized the eastern Syria town of Mayadeen on Thursday, the latest in a series of strategic advances, as the number of people killed in the increasingly violent conflict passed the 40,000 mark.
Defeated government troops fled from Mayadeen to a military airport near the main eastern city of Deir Ezzor, the Syrian Observatory for Human Rights said.
"The area east of the city of Deir Ezzor, on the Iraqi border, is now the largest area in the entire country that is out of army control," said the Observatory's director, Rami Abdel Rahman.
The rebel Free Syrian Army said in an email to AFP that insurgents had captured an important military base on the edge of Mayadeen.
"The FSA took control of an artillery garrison in the outskirts of Mayadeen, after a siege that lasted more than 20 days," said Fahd al-Masri, a spokesman for the FSA.
The oil and gas-rich province of Deir Ezzor is home to Sunni Muslim tribes whose ties extend across the border into Iraq.
"In that area of Syria there are deep tribal loyalties, and fighters in western Iraq help the rebels fight the regime," Abdel Rahman told AFP.
Despite its battlefield losses, most oil and gas fields in the large desert province remain still under regime control, said the Britain-based Observatory, which relies on a network of activists, lawyers and medics on the ground.
Syria's rebels have also overrun vast swathes of territory in northern Syria along the Turkish border and control most border crossings into Iraq and Turkey, cutting off key supply lines for the regime.