Boko Haram extremists murder aid worker Hauwa Mohammed Liman

The 24-year-old nurse had been held hostage since March

Hauwa Mohammed Liman, had been working in a hospital supported by the International Committee of the Red Cross (ICRC), when she was abducted by militants linked to Islamic State in March. (Reuters)

Boko Haram has murdered another aid worker in Nigeria, despite a widespread appeal to save her life.

The victim, identified as Hauwa Mohammed Liman, had been working in a hospital supported by the International Committee of the Red Cross (ICRC), when she was abducted by militants linked to Isis in March.

She was executed on Monday by rebels from a faction of Isis in West Africa, after a deadline expired, officials said.

Local reports stated that a video released by the extremists said Liman deserved death because she had "betrayed Islam" by working for the ICRC.

On Sunday, the ICRC, which does not pay ransoms, had issued a plea saying "we urge you for mercy" and noted that a 24-hour deadline was counting down.

Nigeria's information minister said the government was “shocked and saddened" by the killing, adding that lawmakers “did all within its powers to save her life".

“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,” Mr Alhaji Lai Mohammed said in a statement.

Liman, a 24-year-old nurse and student of Health Education at the University of Maiduguri, was amongst the group of humanitarian workers who were taken hostage in Rann, Kala Balge Local Government Area of Borno State in March.

Her murder comes weeks after insurgents killed Saifura Hussaini Ahmed Khorsa, another ICRC aid worker. Nigerian President Muhammadu Buhari called the killing "an act of extreme barbarism; utterly reprehensible and inhuman."

The terrorists also promised to keep Leah Sharibu, a Christian schoolgirl seized in a mass abduction in February as “a slave for life”. She remains captive over her refusal to convert to Islam, while more than 100 of her fellow students were released.

President Buhari, who declared that defeating the insurgency was a top priority when he took office in 2015, recently sent three Cabinet ministers to meet with the families of Sharibu and the abducted health workers.

In April 2014, the mass abduction of 200 schoolgirls from Chibok, Borno prompted global condemnation.