LAGOS - The spokesman for Islamist militant group Boko Haram has been killed by Nigeria's military, reliable sources have told the BBC.

However, Boko Haram has not confirmed that Abu Qaqa has been killed.

A military spokesman told the BBC that two militant suspects had been arrested, one of whom later died but his identity remains unknown.

Analysts note that Abu Qaqa is an alias, so establishing his identity will not be easy.

The military has previously claimed to have arrested Abu Qaqa but this was denied by Boko Haram, who said the wrong man had been detained.