Boko Haram killed an aid worker and threatened to kill three other hostages, including the Christian schoolgirl Leah Sharibu, in September.
Saifura Hussaini Ahmed Khorsa, 25, who worked as a midwife with the International Committee of the Red Cross, had been abducted on 1 March, alongside two other health workers.
Video message
In a video, the insurgents said: ‘We contacted the government through writing and also sent audio messages but the government have ignored us. So, here is a message of blood,’ said a spokesman of the group. ‘The other nurse and midwife will be executed in similar manner in one month, including Leah Sharibu,’ the spokesman added.
