Pope Francis, the Archbishop of Canterbury and U.N. Secretary-General Ban Ki-moon have strongly condemned the brutal killing of Ethiopian Christians in Libya by extremists claiming to fight in the name of Islam.

Ban said April 20 he "utterly deplores" the targeting of people on the basis of their religious by extremists affiliated with the group calling itself Islamic State of Iraq and the Levant (ISIL).

He expressed his condolences to the families of those who lost their lives as a result of the attack, his office said in a statement.

Pope Francis on April 21 also expressed his "distress and sadness" at hearing of the latest atrocities committed against innocent Christians sending a message to Ethiopian believers.

He said they were killed, "for the sole reason that they are followers of our Lord and Saviour Jesus Christ."

Pope Francis sent his message to Abune Mathias, Patriarch of the Ethiopian Tewahedo Orthodox Church.

"It makes no difference whether the victims are Catholic, Copt, Orthodox or Protestant.

"Their blood is one and the same in their confession of Christ! The blood of our Christian brothers and sisters is a testimony which cries out to be heard by everyone who can still distinguish between good and evil."

Francis said, "We know that the life we live in God's merciful love is stronger than the pain all Christians feel, a pain shared by men and women of good will in all religious traditions."

World Council of Churches general secretary, Rev. Olav Fykse Tveit, also wrote to Patriarch Abune Mathias, expresssing his shock.

"I speak on behalf of the ecumenical family when I say that we are shocked and appalled by the heinous and inhuman violence inflicted on these innocent faithful Ethiopians and that we strongly denounce and condemn any ideology that condones and celebrates murder and torture," he said in the letter issued on 21 April.

"It is in such troubled and challenging times that the gospel imperative of solidarity and ecumenical togetherness with the Ethiopian Orthodox Tewahedo Church is more relevant than ever," Tveit noted.

The Archbishop of Canterbury, Justin Welby, also condemned the Islamic State as "deeply evil" after footage emerged online of extremists executing 30 Christians in Libya.

The footage appeared to show two groups of Ethiopians, one of which was shot while the other group was beheaded.

News agencies reported that the Ethiopians were captured while passing through Libya on their way to Europe.

The extremists were heard describing the victims as "worshippers of the cross belonging to the hostile Ethiopian church."

Ban reaffirmed in his statement that the U.N.-backed political talks remain "the best chance" for Libyans to overcome their country's crisis and encourage the parties to make the necessary compromises to reach an agreement.

"Only by working together will Libyans be able to start building a state and institutions that can confront terrorism," noted Ban.

ISIL, also called IS, can be referred to by its Arabic designation as Da'esh, has taken its fight in past months to Libya during intensified U.N.-backed efforts to aid a political resolution to the country's crisis.