Responding to the news the Prime Minister David Cameron said:
I am appalled by the murder of Christians in Libya, a simply barbaric and inhumane act. My thoughts are with the families of those killed and the UK stands united with the Egyptian people during this period of mourning.
Our efforts to defeat the monstrosity of Islamist extremism must not waver.
The UK remains steadfast in its efforts to defeat ISIL and in its work to bring about a political transition in Libya through the UN. We are clear that Libya must not become a safe haven for terrorists.
Find out more about ISIL: UK government response.