Nigeria's air force said it had killed some senior Boko Haram militants and believed it had fatally wounded the group's leader in a raid on the Islamists' northeast heartland.

Government planes attacked the fighters in the village of Taye inside the Sambisa forest in Borno State on Friday, the air force said, adding it had only just confirmed details of the raid.

"Their leader, so called 'Abubakar Shekau', is believed to be fatally wounded on his shoulders," the statement released on Tuesday from army spokesman Colonel Sani Kukasheka Usman added.

The military has reported Shekau's death in the past, only to have a man purporting to be him appear later, apparently unharmed, making video statements. There was no immediate reaction from the group.