Egyptian warplanes have struck Islamic State targets in Libya, just hours after the extremist group released a grisly video showing the beheading of several Egyptian Coptic Christians it had held hostage for weeks.
An armed forces spokesman announced the strikes on state radio, marking the first time Cairo has publicly acknowledged taking military action in neighbouring Libya, where extremist groups seen as a threat to both countries have exploited the chaos following the 2011 uprising.
The statement said the warplanes targeted weapons caches and training camps before returning safely. It said the "intense strikes" were "to avenge the bloodshed and to seek retribution from the killers."
"Let those far and near know that Egyptians have a shield to protect and safeguard the security of the country and a sword that amputates terrorism and extremism," it said.
Libya's air force meanwhile announced it had launched strikes in the eastern city of Darna, an extremist stronghold that 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 the Coptic Christian hostages was released late Sunday by militants in Libya affiliated with the Islamic State group.
The killings raise the possibility that the extremist group - which controls about a third of Syria and Iraq in a self-declared caliphate - has established a direct affiliate less than 800 kilometres from the southern tip of Italy. One of the militants in the video makes direct reference to that possibility, saying the group now plans to "conquer Rome."
The militants had been holding 21 Egyptian Coptic Christian labourers 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 beheading videos from an Islamic State group affiliate to come from outside the group's core territory in Syria and Iraq, and displayed the sophisticated techniques used in previous videos.
Libya in recent months has seen the worst unrest since the 2011 uprising that toppled and killed longtime dictator Moammar Gadhafi, which will complicate any efforts to combat the country's many Islamic extremist groups.
The internationally recognised government has been confined to the country's far east since Islamist-allied militias seized the capital Tripoli last year, and Islamist politicians have reconstituted a previous government and parliament.
Egypt has strongly backed the internationally recognised government, and US officials have said both Egypt and the United Arab Emirates took part in a series of mysterious airstrikes targeting Islamist-allied forces last year.
