Newly-appointed military brass assigned to fight the country’s jihadist insurgency died in a plane crash in bad weather near Kaduna International Airport in the country’s north.

Nigeria’s top-ranking army commander Lieutenant General Ibrahim Attahiru and 10 other military officers who perished in the crash include Brigadier General M. Abdulkadir, Brigadier General S. Olayinka and Brigadier General A. Kuliya.

Chief of Army Staff Attahiru was appointed by President Muhammadu Buhari in January as part of a shakeup of the top military command to better fight surging violence and a more than decade-long jihadist insurgency.

The US diplomatic mission to Nigeria called Attahiru’s death “a tremendous loss to Nigeria” on Twitter, adding: “We join Nigerians in mourning the tragic loss of life from today’s plane crash.”

Nigeria’s military has been battling Boko Haram in the northeast since 2009 in a conflict that has killed more than 40,000 and displaced some two million.

Attahiru died as reports emerged that the leader of Boko Haram, Abubakar Shekau, , the fundamentalist warlord who turned Boko Haram from an obscure radical sect into a jihadist army whose war with the Nigerian state has left tens of thousands dead across four nations, has died.

The U.S. government’s $7 million reward for his capture made Shekau Africa’s most wanted man.

In 2016, U.S. drones flown from Cameroon spotted his camp, but subsequent Nigerian airstrikes missed their target, accidentally killing at least 10 of the Chibok schoolgirls instead, according to Nigerian officials and several of the hostages who were later released.

Globally, he was known for kidnapping nearly 300 schoolgirls from the town of Chibok on the night before their final exams, an abduction that sparked the world-wide social-media movement #BringBackOurGirls.

His death, which Nigeria’s military has erroneously reported at least three times before, was confirmed by five Nigerian officials who detailed how he detonated a suicide vest during a confrontation with rival insurgents to avoid being taken alive.

According to media reports, two senior officials and two government mediators said Shekau’s killing was orchestrated by fighters from the breakaway Islamic State West Africa Province, or Iswap, who reached Shekau’s base on Wednesday in the Timbuktu region of the Sambisa Forest. To avoid be taken, Shekau reportedly detonated his suicide vest.

“We hope (Shekau’s death) brings down the senseless killings,” said Abba Modu, whose 6-year-old daughter was killed by the sect last year. “Especially the women and children.”