Mystery surrounds the fate of more than 100 teenage girls who were abducted from a school in the remote north-east of Nigeria.
The military says all but eight of the 129 girls have escaped, but parents of the girls say many are still missing.
It is thought Islamist militant group Boko Haram took the girls to forested areas near the Cameroonian border.
The group is waging a bloody campaign for an Islamic state in northern Nigeria.
The BBC’s correspondent in Lagos, Will Ross, says the Nigerian military’s statement that most of the girls had escaped their captors contrasts sharply with other information available to the BBC, including the claims of parents of pupils at the school. They insist “many” of their children are still missing.
The raid on the boarding school is a great source of embarrassment for the Nigerian authorities who say their military campaign against the militants is succeeding, he adds.
Hours before the military issued its statement, the governor of Borno state Kashim Shettima said the vast majority of the girls were still missing and offered a reward of 50m naira ($308,000; £184,000) for information.