Oil giant BP confirmed the identities of three employees killed during the attack on a gas facility in Algeria, on January 16.
26-year-old Sebastian John from Nottingham, 44-year-old Carlos Estrada, originally from Columbia, but living in London as a senior manager for BP, and 58-year-old Gordon Rowan, from Oregon in the US, were killed when Islamist fighters attacked the shared gas facility in northern Algeria.
The men were among 18 BP employees captured during the ambush.
David Cameron warned that north Africa is becoming a "magnet for jihadists" as he announced help to tackle the terror threat in the region.
A British man from Aberdeenshire has spoken to ITV News about his dramatic escape from militants and his concern for some of his colleagues.
Stephen McFaul, one of dozens of hostages taken by Islamist fighters at gas plant in Algeria, is due to arrive back in Belfast later today.