In a late-night assault by gunmen in central Nigeria, at least 26 members of the Nigerian security forces were killed and eight others were injured, according to two military sources reported by AFP.

In addition, an air force spokesman reported that a helicopter that was rescuing wounded crashed on Monday morning in the area where the army is combating criminal groups, without mentioning if the crew and passengers were still alive.

The two military personnel requested anonymity because they were not authorized to speak about the incident and because military authorities were not readily available for comment.

“We lost 23 soldiers, including three officers, and three Civilians JTF (vigilantes) in the encounter while eight soldiers were injured,” said the first source, following “a serious fight” along the Zungeru-Tegina highway.

The same toll was given by a second officer, who also reported that "heavy casualties" were sustained by the robbers. Additionally, he claimed that a military helicopter sent out to evacuate the wounded, which was carrying 11 dead and 7 injured, had lost communication.

A Nigerian air force spokesman confirmed that its Mi-171 helicopter while on a “casualty evacuation mission” crashed on Monday after take-off from Zungeru.

“The aircraft had departed Zungeru Primary School en route for Kaduna but was later discovered to have crashed near Chukuba Village in Shiroro Local Government Area of Niger State,” spokesman Edward Gabkwet said in a statement.

He stated that efforts were being made to rescue people on board and that preliminary inquiries into the crash's cause had begun.

In the northwest and center of the country, where criminals known as "bandits" frequently conduct attacks and kidnappings, not a week goes by without such incidents.

The gangs, which have a history of mass school kidnappings, keep camps in a huge forest that crosses the states of Niger, Kaduna, Zamfara, and Katsina.

Bandits have terrorized northwest and central Nigeria for years, storming into remote villages to kill and kidnap residents for ransom, torch houses after robbing them, and stealing valuables.