The United States conducted airstrikes against two facilities used by Iran’s Revolutionary Guard and its proxies in eastern Syria late Sunday, Pentagon officials said, in the latest retaliation for what has become a daily barrage of rocket and drone attacks against American forces in Iraq and Syria.

Air Force F-15E fighter jets struck several buildings in Abu Kamal used for training and storing munitions, and a safe house in Mayadin used as a command headquarters.

The strikes came just four days after American warplanes hit a munitions warehouse in eastern Syria. Pentagon officials say the two latest sets of strikes, as well as one on Oct. 27, were meant to deter Iran and the militias it supports in Syria and Iraq, which the Biden administration has blamed for the attacks.