The Nigerian army said Tuesday it had fatally wounded terrorist group Boko Haram's leader in an air attack, also killing several commanders.

Several media reported that Boko Haram commanders confirmed dead include Abubakar

Mubi, Malam Nuhu and Malam Hamman, among others.

Abubakar Shekau, also known by the alias Darul Akeem wa Zamunda Tawheed, or Darul Tawheed, served as deputy leader to Boko Haram's founder Mohammed Yusuf, until Yusuf was executed in 2009. Nigerian authorities believed that Shekau was killed in 2009 during clashes between security forces and Boko Haram until July 2010, when he appeared in a video claiming leadership of the group.

The Nigerian government is fighting insurgency in the country's northeast, where a number of extremist groups, including Boko Haram, have been active for years.

Boko Haram began large-scale attacks in northeast Nigeria in 2009. Last year, the group expanded attacks into neighboring Niger, Cameroon and Chad. The extremist group pledged allegiance to the Islamic State terrorist group, outlawed in Russia and many other countries, in March 2015.