At least eight people were killed on Saturday when a car bomb exploded in a market in eastern Syria near the border with Iraq, a monitoring group said.
The blast occurred in the town of al-Mayadin, which lies on the Euphrates River in the Deir al-Zor province, the British-based Syrian Observatory for Human Rights said.
The Observatory, which monitors violence in Syria through a network of sources, also said a number of people were seriously wounded in the blast but did not give a number.
The area is a power base for the Islamic State in Iraq and the Levant (ISIL), an al Qaeda splinter group active in Syria and Iraq, whose forces this week seized several major towns in northern Iraq and swept south towards Baghdad.
ISIL has been battling al Qaeda's affiliate, the Nusra Front, and other insurgents in the Deir al-Zor province for months for control of oilfields and strategic sites. The fighting has killed hundreds and forced tens of thousands to flee their homes.