GENEVA (Reuters) - The Red Cross on Tuesday named a health worker abducted and murdered by her Islamist captors in Nigeria as 24-year-old midwife Hauwa Mohammed Liman and said it had refused to pay a ransom for her release.

Members of the Bring Back Our Girls (BBOG) movement carry banners ahead of a march to condemn the killing of a medical aid worker and asking for the release of schoolgirl Leah Sharibu, 15, who was abducted in February from her school in the town of Dapchi, in Abuja, Nigeria October 16, 2018. REUTERS/Afolabi Sotunde

A senior official of the International Committee of the Red Cross (ICRC) told Reuters it had decided not to pay a ransom as it would set a dangerous precedent for the 16,000 aid workers it deploys in 80 countries worldwide.

The Nigerian government on Monday said a medical aid worker held hostage by Islamic State in West Africa (ISWA) militants was killed after a deadline they set expired.

The ICRC said in a statement it received information that Liman, who worked in a hospital supported by the Geneva-based aid agency, had been killed “in a despicable act of cruelty”.

The agency had issued a public appeal to her captors at the weekend to spare her life after a threat was received.

“When health care workers are captured or abducted there is always a demand,” Patricia Danzi, ICRC regional director for Africa, told Reuters on Tuesday.

“We are a humanitarian organization so we cannot enter into such kind of negotiations. So we always ask for unconditional release. And that’s what we did. That was the plea.

“We believe that there is no cause that can justify an execution of a young healthcare staff (worker),” she added.

Danzi said the ICRC was not planning to suspend its operations in northern Nigeria or to withdraw.

“We are now in a period of mourning...Then we will have to rethink what we can do. And the (security) guarantees we can get,” she said.

“Because we want to give humanity a chance, we want to be there for the people that still need our help.”

Nigeria is the ICRC’s second largest operation in Africa and its aid workers help 80,000 mainly displaced people in the northeastern town of Rann.

Liman and two other Nigerian aid workers, Alice Loksha and Saifura Hussaini Ahmed Khorsa, were working in Rann when they were kidnapped by ISWA in March.

Khorsa, also a midwife, was killed in September.

Loksha, employed by a UNICEF-supported center, remains a captive, along with Leah Sharibu, a 15-year-old Nigerian student abducted by the group in a separate incident in February, the ICRC said, appealing for the two women’s safe release.

ISWA, an Islamic State offshoot, split from Boko Haram - the main Islamic militant group in Nigeria - in 2016. Its fighters have killed hundreds of soldiers in attacks in northeastern Nigeria in the past few months.

At the entrance to the ICRC headquarters in Geneva, a table was set up with a photo of Liman, along with a white orchid plant, a burning candle and a sign asking staff to write their condolences for her family.