Egypt retaliated Monday against Islamic State in Iraq and Syria (ISIS) targets in Libya following the beheading of more than a dozen of its Coptic Christian citizens, according to media reports.
The early morning strike via F-16 jets marks the first time Cairo has publicly acknowledged military intervention in its western neighbor, which has been beset by militant violence since the 2011 uprising that killed leader Moammar Gadhafi.
Egypt's assault, made in coordination with the Libyan military, hit ISIS-affiliated targets near the city of Darna, and resulted in scores of jihadis killed, as well as at least five civilians, according to security officials.
"What is happening in Libya is a threat to international peace and security," said Egyptian President Abdel Fattah el-Sissi in a statement banning travel to Libya by Egyptian citizens.
Hours earlier, ISIS released a five-minute execution video — one of the first from outside its stronghold in Mesopotamia — showing the beheading of several captured Egyptian Christians on a beach.
"The sea you have hidden Sheikh Osama bin Laden's body in, we swear to Allah, we will mix it with your blood," a masked militant says in English in the video.
Officials in Cairo said 21 laborers had been captured from the Libyan costal city of Sirte, where they had gone looking for work. None are believed to survive.
The White House strongly condemned the slayings, with spokesman Josh Earnest saying ISIS's "barbarity knows no bounds" in a Sunday statement.
“We call on all Libyans to strongly reject this and all acts of terrorism and to unite in the face of this shared and growing threat,” he said.
Egypt has also been battling ISIS-allied jihadis in the Sinai Peninsula, where dozens were killed in assaults last month.