According to TheCable, the insurgents have also vowed to keep Dapchi schoogirl Leah Sharibu as a slave for life.
Liman's killing was done spite of a last-minute passionate appeal by the International Committee of the Red Cross (ICRC) "to the Nigerian Government and to communities and individuals with influence to work toward the release of two committed medical workers abducted in north-eastern Nigeria earlier this year".
In a short statement, ISWAP said: “We have kept our word exactly as we said, by killing another humanitarian worker, Hauwa Leman, who is working with the International Committee of the Red Cross (ICRC) that were abducted during a raid on a military facility in Rann, Kala Balge in March 2018.
“Saifura and Hauwa were killed because they are considered as Murtads (apostates) by the group because they were once Muslims that have abandoned their Islam, the moment they chose to work with the Red Cross, and for us, there is no difference between Red Cross and UNICEF.
“If we see them, we will kill the apostates among them, men or women, and chose to kill or keep the infidels as slaves, men or women.”
The 24-year-old nurse and student of Health Education at the University of Maiduguri was among the three aid workers abducted by the insurgents in an attack on a heavily-guarded military facility in the small town of Rann, Borno State on March 1, 2018.
Aside Liman, the insurgents also abducted Alice Loksha Ngaddah, a nurse and mother of two, and Saifura Husseini Ahmed, a midwife. They killed four soldiers and four policemen as well.
Ngaddah’s aged mother died unexpectedly in April as a result of the trauma of her daughter’s abduction, while Saifura was killed in September.
After killing Liman, ISWAP said Ngaddah, a Christian who works with UNICEF, will be kept as a slave, just like Leah Sharibu.
“From today, Sharibu and Ngaddah are now our slaves," it said. “Based on our doctrines, it is now lawful for us to do whatever we want to do with them."