The mother of one of the 21 Egyptian Copts killed by Islamic State (IS) in Libya in February has said that she is thankful her son "died for the cross".

Milad Makeen Zaky's mother spoke of her son in a video posted on the Facebook page of International Christian Concern, which works to highlight the plight of Christians persecuted for their faith. It was recorded soon after the video of the beheadings was released.

Appearing dignified and composed, she says: "I thank God that my son kept the faith and died for the cross, because he was the son of Christ from his birth, not my son."

Milad had travelled to Libya to find work because it was hard to make a living in Egypt, his mother explained.

"From his childhood he was going to Sunday school, reading the Holy Bible, attending the prayer meetings in the church community," she said.

"We thank God that he kept the faith."

The 21 Christians were kidnapped by IS and held for several weeks before the killings. The IS video entitled 'A Message Signed With Blood to the Nation of the Cross', showing the Christians in orange jump-suits accompanied by black-clad jihadis, whose images are believed to have been digitally altered to make them appear larger, horrified the world.

A video from the SAT-7 ARABIC TV station featuring the brother of one of the men killed was widely shared. Beshir Kamel thanked Islamic State for not editing out the men's declaration of belief in Christ because he said this had strengthened his own faith. He added that the families of the ex-patriate workers are "congratulating one another" and not in despair: "We are proud to have this number of people from our village who have become martyrs," he told the programme.

He said: "Since the Roman era, Christians have been martyred and have learned to handle everything that comes our way. This only makes us stronger in our faith because the Bible told us to love our enemies and bless those who curse us."