A leading US charity is building homes for the families of the 20 young Coptic Christians martyred by Islamic State earlier this year.

Focus on the Family has stepped in to help the relatives of the Egyptians, whose murders by beheading on a beach near Tripoli were vidoed and posted on social media, stunning the world with the brutality. The 20 Egyptians and their Ghanaian co-worker were from poor and marginalised communities and were in Libya working.

Jim Daly, president of Focus on the Family, wrote on his blog: "They were attempting to provide for their impoverished families living in Egypt when they were taken hostage and beheaded because of their Christian faith."

Sami Yacoub, regional director of Focus on the Family, stepped in immediately to talk to the families in the Egyptian village of Samalout and Daly described their reactions as "astonishing".

He said: "A number of them shared how their pain soon gave way to joy. They spoke of a desire to share their faith with the ISIS extremists who committed the atrocious acts. They rejoiced that the martyrs were now home with Jesus Christ. Their only prayer request? 'Please pray our faith remains strong'."

However, he noted that the families were urgently in need of rehousing.

Daly wrote: I'm thrilled to report that God has used the construction efforts to bring the community together. Our Focus team has been able to hire labourers from surrounding villages, giving them a source of income as well as a sense of pride in helping these families in need."

The Focus team has also been meeting with the wives of the martyrs and their children, parents and siblings.

Daly wrote: "It brings us great joy to get to see these houses go up as a sign of love and unity within the global Church. It's amazing to see how God's presence reigns sovereign even in the midst of a horrible tragedy."

Focus on the Family reported on its website that Egypt and especially members of the Coptic faith were "deeply shaken" by the murders.

Focus said: "All of these young Christians were in their early to mid-20s, and they went to Libya in search of work to help feed their families living under the poverty line in Egypt. They literally had nothing, except for the very thing they died for because they would not let it go — their faith in Christ. Their families echoed that faith. They did not curse ISIS. They did not ask for pity. They did not ask for supplies or money."

One elderly lady, whose son was among those murdered and who is now looking after her grandchildren, was asked how they would survive now. She said: "Our God has always provided for our every need, and He will continue to provide."

The families and friends of those martyred prayed that their children would forgive ISIS and they would all hope to make the same choice, if faced with the same threat. "It was a stirring challenge to the team from Focus on the Family Middle East, and to Christians everywhere," Focus said, adding that the houses are not extravagant but they are safe, provide shelter and they give members of a marginalised community a place to call home.

"More than that, they are a physical demonstration of unity within the worldwide body of Christ."

The project will also include a memorial community centre in honour of the martyrs.