Updated

U.S. forces in Syria were injured Friday from Iranian rocket attacks targeted American outposts, Fox News has learned. 

The attacks occurred in Deir Ezzor in eastern Syria. A senior U.S. defense official said there were two separate attacks carried out by Iranian proxy forces targeting two U.S. bases. 

One was a rocket attack and the other involved multiple Iranian drones, the official said. The number of casualties has not been disclosed but some may be serious. The Pentagon was assessing its response. 

US BASE IN SYRIA ATTACKED BY IRANIAN PROXY FORCES AFTER RETALIATORY AIRSTRIKES

Military troops

Troops from the Syrian Democratic Forces (SDF) Special Operations and the U.S.-led anti-jihadist coalition take part in heavy-weaponry military exercises in the countryside of Deir Ezzor in Syria, on March 25, 2022 (Photo by Delil Souleiman/AFP via Getty Images)

The attacks came after an American contractor was killed by a suspected Iranian drone that hit and injured six servicemen in northeast Syria. 

U.S. intelligence has assessed that the drone that struck the base was Iranian. The injured U.S. service members were in "stable" condition and have been transported to a hospital in Landstuhl, Germany, a senior U.S. defense official told Fox News Friday.

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The IRGC – Iran’s primary branch of its armed forces – has backed Syrian forces under Bashar al-Assad for the past decade following the breakout of the civil war in 2011.

The U.S. has since aided the Syrian Free Army in eastern Syria in what some have argued has become a proxy war between the U.S. and Iran.