A man inspects a damaged site after what activists said were airstrikes by forces loyal to Syria's President Bashar al-Assad in the Damascus suburb of Ain Tarma May 16, 2015.
Reuters/Amer Almohibany

At least 32 Islamic State members, including four of its leaders, were killed in air strikes and a U.S. special forces raid that targeted the group in eastern Syria, a group monitoring the Syrian war said on Sunday.

U.S. officials said the raid killed a senior Islamic State leader identified as a Tunisian who helped to manage its black-market sales of oil and gas to raise funds. A U.S. official said that about a dozen fighters were killed in the raid.

British-based monitoring group the Syrian Observatory for Human Rights gathers its information from sources in the region.

The operation in the eastern Deir al-Zor province marked a departure from Washington's strategy of relying primarily on air strikes to target militants in the area.

(Writing by Tom Perry; Editing by David Goodman)