Syrian rebels captured an army artillery base in the eastern oil producing province of Deir al-Zor on Thursday, weakening President Bashar al-Assad's control of the strategic region bordering Iraq, several opposition sources said.

"The Mayadeen military base fell at 8.30 a.m. (0630 GMT)," Abu Laila, an official in the Military Revolutionary Council in the province, told Reuters. He said 44 rebel fighters had been killed in the siege of the base.

"The whole countryside, from the Iraqi border and along the Euphrates to the city of Deir al-Zor, is now under rebel control."

Another opposition source in contact with rebels confirmed that the base, 42 km south-east of the city of Deir al-Zor, had fallen.

The capture of the base follows that of a military airport 80 km to the south-east on the Iraqi border last week. Rebels have stormed several bases in the north and centre of the country, indicating growing military strength, according to opposition sources and diplomats.

But no major city has fallen to the opposition and Assad's airpower has ensured that rebels' hold on many parts of the country remains tenuous. Attempts to bring rebels under unified command have made little progress.

Sheikh Nawaf al-Bashir, a tribal leader from the province said the fall of Mayadeen leaves Assad with three major army bases left under his control in the province.

The main road to Iraq, from the outskirts of the city to the border crossing of Albu Kamal, is now with rebels, he said.-Reuters