The Islamic State West Africa Province (Iswap) which is a Boko Haram splinter group have killed one of six hostages being held in north – east Nigeria.
The BBC reports that the aid workers have been held since July when their convoy was attacked.
The aid group Action Against Hunger says one of its employees, two drivers and three health ministry personnel were being held but could not say which of them had been killed.
Meanwhile, last week the Nigerian army banned Action Against Hunger from continuing to work in the country saying it was supporting Boko Haram.
Iswap has also claimed killing two Nigerian soldiers it has been holding hostage although the government is yet to comment on the reports.
In the mean time, Action Against Hunger has condemned the killing of one of its hostages and called for the urgent release of those being held by the militants.