AMMAN, Aug 3 (Reuters) - Syrian rebels seized a security headquarters in the oil-producing province of Deir al-Zor on Friday, killing 13 security personnel in battles to control a major highway leading to Iraq, a rebel spokesman said.
President Bashar al-Assad's forces have lost control over large swathes of Deir al-Zor in the last two months, but troops still surround the provincial capital, pounding the city with artillery and from the air.
On Friday evening, the rebels stormed a complex for political security and other buildings near the town of al-Mayadeen, halfway between the provincial capital and the border with Iraq, said Omar Abu Laila, a spokesman for the Eastern Military Revolt Council.
He said several security personnel had defected over the last few days and that "13 who remained defending the complex" had been killed.
Three intelligence agents were captured, he added.
"The fighters are now in control of the outpost," Abu Laila said by phone from the province. "There is still one army outpost and an artillery position under the control of the regime near Mayadeen."
Another rebel source said the rebels were trying to cut off the army's highway supply line to the town of Albu Kamal on the border with Iraq. Opposition fighters briefly took over a crossing point last month but withdrew when the Iraqi authorities closed the border from their side.
Deir al-Zor is a tribal Sunni Muslim region on the Eurphrates river that cuts through the country's eastern desert.
An alliance forged by Assad's father, the late President Hafez al-Assad, and Deir al-Zor tribes disintegrated when Assad sent tanks a year ago into urban areas of the province to put down pro-democracy demonstrations.