Egypt says it has bombed Islamic State of Iraq and Syria targets in Libya as revenge for a mass beheading of Egyptian Christians on a Libyan beach.

Egypt’s military government targeted weapons caches and training camps on Monday in order “to avenge the bloodshed and to seek retribution from the killers,” Egyptian military officials said in a statement. The attacks were in response to a video released Sunday by Islamic State militants showing the beheading of 21 Coptic Christians who were being held hostage.