Two U.S. Air Force F-15E Strike Eagles struck two Iranian-backed Syrian militia targets with 20 GBU-39 Small Diameter Bombs (SDBs) in retaliation for recent assaults against U.S. personnel, including an attack on March 23 by a “kamikaze” drone–likely supplied by Iran–that killed a U.S. contractor and wounded U.S. service members at a U.S. coalition base in Hasaka in northeast Syria, DoD officials said.

Boeing [BA] builds the F-15E and SDBs.

Defense Secretary Lloyd Austin “at the direction of Pres. Biden authorized U.S. Central Command forces to conduct precision strikes into eastern Syria against facilities used by groups affiliated with Iran’s Islamic Revolutionary Guard Corps [IRGC],” Air Force Brig. Gen. Pat Ryder, a DoD spokesman told reporters on March 24.

The F-15Es “struck two IRGC-affiliated facilities at approximately 7:40 p.m. Eastern time, or 2:40 a.m. local [time],” Ryder said. “The facilities were located…in eastern Syria, and we’re continuing to assess the outcome of the strikes. Initial indications are that the facilities were destroyed.”

“In regards to any militant casualties, we’re still assessing,” he said. “These precision strikes were intended to protect and defend U.S. personnel, and the U.S. took proportionate and deliberate action intended to limit the risk of escalation and minimize casualties.”

DoD did not offer an explanation as to how a relatively slow drone could hit the base at Hasaka without U.S. radar detecting it and the U.S. intercepting it.

“My understanding is that there was a complete site picture in terms of radar,” Ryder said on March 24. “As is the case in any type of attack, U.S. Central Command will conduct a review to assess what happened and take a look at what, if any, mitigating actions need to be taken.”