Human Right Watch has called the brutal killing of 21 Egyptian Christians by Islamic State militants in Libya a "war crime," while urging investigations by Egypt and Libya into civilian casualties reportedly caused by the ensuing coordinated airstrikes on the extremists.
The ultra-hardline group released a grisly video late on Sunday showing the beheading of 21 Egyptian Christians who had travelled to the North African State to seek work, promoting Egypt to launch airstrikes against Islamic State targets in eastern Libya hours later.
“ISIS is again horrifying the world by perpetrating war crimes, this time showing no mercy in Libya,” said Sarah Leah Whitson, Middle East and North Africa director, in a statement issued on Tuesday.
“But any military engagement with ISIS should take all possible steps to spare civilian lives," she added.
The New York-based watchdog called on the United Nations and the International Criminal Court (ICC) prosecutor to investigate the incident as well as other "crimes against humanity" in Libya.
President Abdel-Fattah El-Sisi said "there is no choice" but to have an UN-backed coalition to combat the militants in Libya, in an interview aired on Tuesday by France's Europe 1 radio.
Egypt, in coordination with Libyan authorities, carried out airstrikes against Islamic State targets, including training camps and arms depots in the eastern Libyan city of Derna, killing 40 to 50 militants, according to the Libyan Air Force.
HRW cited a local resident as saying that at least six civilians, including a woman and her three children, were killed in the attacks.
"Libya and Egypt should both conduct investigations into the civilian casualties of these air strikes, and Egypt needs to take steps to minimise such casualties," the rights group said.
"All parties to the conflicts in Libya, which now includes Egypt, are required to abide by the laws of war. This requires them to take all feasible steps to protect civilians," it added.
Libyan air force Chief Saqr Al-Jaroushi told an Egyptian broadcaster Monday that his country's forces bombed at least one civilian residence hosting anti-aircraft weaponry.
And Egyptian foreign minister Sameh Shoukry said in an interview on Tuesday with the CNN that Egypt's air raids were meant to be "intense and target particular sites," adding that his country will examine the incident and ensure the "highest possible cautiousness."
Monday's air strikes, which Cairo said were in self-defense, were the first time Egypt announced military action against militia targets in Libya. The United Sates had said Egypt last year allowed the United Arab Emirates to use its bases to bomb militia fighters there.
Hundreds of thousands of Egyptians remain in the North African state, with Egyptian officials saying they would be transferred back home.