A monitoring group says four days of heavy fighting between rival Islamic rebel groups has killed 62 fighters in eastern Syria.
The Britain-based Syrian Observatory for Human Rights said the fighting also forced hundreds of civilians to flee their homes in the oil-producing eastern province of Deir al-Zour.
The clashes involved fighters from the Al-Qaeda-linked Nusra Front and the Al-Qaeda breakaway group known as the Islamic State of Iraq and the Levant (ISIL).
Rebels from the two rival Islamic groups have fought each other for months over territory they previously captured together from President Bashar al-Assad's forces.
UN Calls For More Refugee Aid
Meanwhile, in related news, the United Nations refugee agency has criticized donors for not doing enough to help millions of Syrian refugees and the countries hosting them.
UN High Commissioner for Refugees Antonio Guterres said at a meeting of senior officials from Egypt, Jordan, Iraq, Lebanon and Turkey on may 4 that the Syria crisis demanded "massive support."
Speaking at the Zaatari refugee camp in northern Jordan, Guterres said that "there has been very little support" for the refugees.
The Zaatari camp is home to more than 100,000 Syrians.
Syria's civil war has triggered a huge refugee crisis, with half the population having fled their homes, including nearly three million refugees mainly sheltering in neighboring countries.
Elsewhere, UN chief Ban Ki-moon told Al Arabiya television on May 4 that "bureaucratic resistance" by Syrian President Bashar al-Assad's government was preventing aid from getting to millions of Syrians.
Based on reporting by Reuters, AP, and AFP