Egypt said Monday it has launched airstrikes against Islamic State targets in Libya after the group released a grisly video showing the beheading of several Coptic Christians it had held hostage for weeks.

A spokesman for the Armed Forces General Command announced the strikes on state radio Monday, marking the first time Cairo has publicly acknowledged taking military action in neighboring Libya, where groups seen as a threat to both countries have taken root in recent years.

The statement said the warplanes targeted weapons caches and training camps before returning safely. It said the strikes were “to avenge the bloodshed and to seek retribution from the killers.”

“Let those far and near know that Egyptians have a shield that protects them,” it said.

Libya’s air force meanwhile announced it had launched strikes in the eastern city of Darna, which was taken over by an Islamic State affiliate last year. The announcement, on the Facebook page of the Air Force Chief of Staff, did not provide further details.

The video purporting to show the mass beheading of Coptic Christian hostages was released late Sunday by militants in Libya affiliated with the Islamic State group.

The killings raise the possibility that the group – which controls about a third of Syria and Iraq in a self-declared caliphate -has established a direct affiliate less than 500 miles (800 kilometers) from the southern tip of Italy. One of the radicals in the video makes direct reference to that possibility, saying the group now plans to “conquer Rome.”

The radicals had been holding 21 Egyptian Coptic Christian laborers rounded up from the city of Sirte in December and January. It was not clear from the video whether all 21 hostages were killed.

It was one of the first such beheading videos from an Islamic State group affiliate to come from outside the group’s core territory in Syria and Iraq. SAPA