Nigeria's military says some officers are selling arms and ammunition to Boko Haram, indicating the corruption bedeviling the country's fight against the Islamic extremists continues despite government efforts to halt graft.

The admission comes three weeks after the Nigerian army said a military tribunal is trying 16 officers and troops accused of offenses related to the fight against Boko Haram, including the theft and sale of ammunition.

Maj. Gen. Lucky Irabor, the theater commander in northeastern Nigeria, told a news conference on Thursday that military authorities have confirmed that some soldiers were selling arms and ammunition to Boko Haram. He called it a betrayal of the Nigerian people.

President Muhammadu Buhari has blamed corruption for the deaths of thousands in the seven-year Islamic uprising that has killed more than 20,000.