The clashes between Al-Qaeda's Syrian branch Al-Nusra Front and the Islamic State of Iraq and the Levant (ISIL) have prompted 60,000 people to flee towns in the oil-rich province.
The sources said 58 fighters on both sides had been killed in the clashes on Monday, along with five civilians.
The deaths bring to 150 the toll since the latest confrontation between the groups erupted last week in Deir Ezzor, bordering Iraq, AFP reported.