Israeli airstrikes targeted Hezbollah-operated drone facilities in Beirut’s southern suburbs and southern Lebanon late Thursday, drawing swift condemnation from Lebanese leaders who said the attacks violated a fragile ceasefire agreement brokered in November.

The Israeli military said the strikes hit underground compounds used to manufacture and store drones, accusing the Iran-backed group of expanding its UAV capabilities with direct support from Tehran.

The facilities were embedded in densely populated areas, according to Israel, which said precautions were taken to minimize civilian harm.

Lebanese President Joseph Aoun called the assault a “flagrant violation” of international agreements and criticized its timing, coming on the eve of Eid al-Adha, one of the most sacred festivals in the Muslim calendar.

The Lebanese army echoed the condemnation and warned it could suspend cooperation with the U.N.-led committee monitoring the truce.