U.S. Central Command (USCENTCOM) conducted air strikes on facilities used by Iran’s paramilitary guard in Syria Tuesday at President Joe Biden’s direction, the command confirmed to the Daily Caller News Foundation.

Targets included bunkers belonging to Iran’s Islamic Revolutionary Guard Corps (IRGC), which has been implicated in a plot to assassinate top U.S. national security officials, used for ammunition storage and logistics support in Syria, CENTOM communication director Col. Joe Buccino told CNN. The strikes targeted 11 of 13 known bunkers in an effort to avoid incurring human casualties, and successfully hit nine.

“Today’s strikes were necessary to protect and defend U.S. personnel. The United States took proportionate, deliberate action intended to limit the risk of escalation and minimize the risk of casualties,” Buccino said in a statement.

CENTCOM called off plans to target the final two bunkers after discovering evidence of a small group of people nearby, CNN reported. The report did not specify whether the individuals were IRGC members.

“The strike in eastern Syria was in response to attacks by Iran-backed groups against US forces in Syria on August 15th and demonstrates our resolve to defend US forces and equipment,” CENTCOM commander Gen. Erik Kurilla told CNN.

Statement from General Michael “Erik” Kurilla, commander of USCENTCOM:

“The strike in eastern Syria was in response to attacks by Iran-backed groups against US forces in Syria on August 15th and demonstrates our resolve to defend US forces and equipment.”

— U.S. Central Command (@CENTCOM) August 24, 2022

The strike on targets associated with the IRGC comes as negotiations between the U.S. and Iran to reach an agreement on sanctions relief and nuclear nonproliferation near a climax. Biden has persisted with the negotiations even after revelations the IRGC sponsored attempts to assassinate former Secretary of State Mike Pompeo and former National Security Adviser John Bolton.

Biden has reportedly refused to accede to Iran’s demands that the U.S. delist the IRGC from the State Department’s list of Foreign Terrorist Organizations.

On Aug. 15, rockets struck the area near U.S. troops housed in Syria’s Green Village base, and a January attack damaged the base and a nearby mosque, according to The Hill, but no U.S. troops were harmed.

Coalition forces did not attribute the August attack to a specific adversary, but Iran-backed militia groups frequently target U.S. and Syrian forces stationed in the region, CNN reported.

About 900 U.S. coalition troops remain in Syria to assist the Syrian Democratic Forces with containing the Islamic State terrorist group. A separate U.S. strike in Syria killed senior Islamic State commander Maher al-Agal.

Syria did not immediately acknowledge the attack, The Associated Press reported. Iranian Foreign Ministry Spokesman Nasser Kanaani later condemned the U.S. strikes and denied any link between Iran and the targeted groups in Syria.

The White House, the Pentagon, did not immediately respond to the DCNF’s requests for comment.