The Islamic State (ISIS/ISIL) wing in West Africa, a faction of the Boko Haram jihadist group, killed a second International Committee of the Red Cross (ICRC) aid worker within a month after a deadline for negotiations of release expired, the Nigerian government revealed on Monday.

Lai Mohammed, the minister of information and culture in Nigeria, reportedly described the killing as “dastardly, inhuman and ungodly,” and vowed to push for the release of two remaining female captives — an aid worker and a 15-year-old Christian girl — held by the jihadist group since earlier this year.

According to the Agence France-Presse (AFP) news agency, the minister added:

It is very unfortunate that it has come to this. Before and after the deadline issued by her abductors, the federal government did everything any responsible government should do to save the aid worker. As we have been doing since these young women were abducted, we kept the line of negotiations open all through. In all the negotiations, we acted in the best interest of the women and the country as a whole.

We are deeply pained by this killing, just like we were by the recent killing of the first aid worker. However, we will keep the negotiations open and continue to work to free the innocent women who remain in the custody of their abductors.

Islamic State-West Africa Province (ISWAP) kidnapped its latest victim —Hauwa Mohammed Liman — alongside two other IRGC aid workers during an attack on a Nigerian military facility in March. So far, the terrorist group has killed two of the captives — Liman and Saifura Hussaini Khorsa.

AFP reported:

Three female health workers were kidnapped during a Boko Haram raid on the remote town of Rann, in Borno state, on March 1 that killed three other aid workers and eight Nigerian soldiers. Two of the kidnapped women, Hauwa Liman and Saifura Khorsa, worked for the International Committee of the Red Cross (ICRC), while the third, Alice Loksha, worked for the [United Nations] children’s agency, UNICEF.

ISWAP has reportedly said it plans to keep the remaining hostages, both Christians, as slaves.

“Last month, the ICRC received a video showing the killing of Ms Khorsa. Exactly a month later, on Monday, another video appeared showing the killing of Ms Liman. A local reporter, who said he had seen it, reported that Ms Liman was shot at close range,” BBC pointed out.

The ICRC said [Liman] was a “sociable, dynamic and enthusiastic woman who was much loved by family and friends. She was truly dedicated to her work helping vulnerable women in her family’s home area.”

Nigeria’s government has not made Boko Haram’s demands public, BBC noted, adding, “It is unclear why the ICRC would be targeted when it acted as an intermediary between the government and Boko Haram for the release of the Chibok girls in 2017.”

In a statement released after Liman’s execution, the ISIS West Africa wing said the aid workers were killed because they had “abandoned their Islam the moment they chose to work with the Red Cross.”

ICRC noted that it had attempted to convince the Boko Haram offshoot to release the aid workers.

The aid group said it had “made sustained and committed efforts to secure the release of the three health-care workers, including a last-minute plea for mercy on Sunday to the Islamic State’s West African province group, to no avail.”