The U.S. military launched another wave of “large-scale strikes” against Islamic State targets in Syria, continuing its campaign of retaliation for an attack last month that killed three Americans.

U.S. Central Command (CENTCOM) announced the latest airstrikes in a statement, saying the operations were carried out around 12:30 p.m. ET on Saturday and targeted multiple ISIS positions across Syria.

The new strikes follow the initial retaliatory operation on Dec. 19, known as Operation Hawkeye Strike, which was conducted jointly by U.S. and Jordanian forces. Since that first response, the U.S. military has continued additional raids aimed at degrading ISIS networks and preventing further attacks.

The military campaign was launched in response to the Dec. 13 attack in Palmyra, Syria, in which two U.S. soldiers and a civilian interpreter were killed by a lone ISIS gunman, who was later shot and killed.

“Today’s strikes targeted ISIS sites throughout Syria as part of our ongoing commitment to eliminate Islamic terrorism threatening our warfighters, prevent future attacks, and protect American and partner forces in the region,” CENTCOM said in its statement. “U.S. and coalition forces remain resolute in pursuing terrorists who seek to harm the United States.”