MAIDUGURI, Nigeria (Reuters) - Campaigners for more than 200 girls kidnapped by Boko Haram from their school in Chibok in northeastern Nigeria two years ago raised doubts on Friday about army reports that a second girl from the group of abductees had been rescued.
The army said late on Thursday a girl among 97 women and children freed this week by soldiers from Boko Haram captivity was one of the missing Chibok girls.
Amina Ali Darsha Nkeki, the first Chibok girl to be rescued, was found by soldiers and vigilantes on Tuesday south of Maiduguri, capital of Borno state and the epicenter of Boko Haram's seven-year insurgency to set up an Islamic caliphate.
Amina and her four-month-old baby were greeted on Thursday in a highly publicized event by President Muhammadu Buhari, the former military ruler who made crushing Boko Haram a central pillar of his 2015 election campaign.
Hours later, the army said a girl from a second rescued group - Serah Luka from Madagali, a town in Adamawa, the state next to Borno - had also come from the Chibok school and had been among those seized in April 2014.
But campaigners cast doubt on the assertion.
"We've cross-checked the list of those missing but the second girl isn't on the list," said Auwa Biu, an activist from the #BringBackOurGirls campaign who nevertheless admitted the possibility of mistaken identity. "Maybe she has other names."
Other campaigners have also said that the number for the missing girl given by the army - 157 - did not tally with the name of the abductee listed in the register.
Hosea Tsambido, who chairs the Chibok Community in Abuja, said Serah did attend the Chibok school but was abducted in a separate incident, not the night-time mass kidnapping that sent waves of revulsion around the world.
Instead, she had been kidnapped from Madagali, he said.
"Madagali was attacked severally, so I don't know the particular time that she was abducted there, but she was not abducted that night at Government Secondary School, Chibok," he told Reuters.
Army spokesman Sani Usman stood by his statement.
"It is an incontrovertible fact that that girl was among those girls that were abducted from Government Secondary School, Chibok, on 14 April 2014".
He said Serah's father and the Chibok headteacher had confirmed the timing of her abduction. Reuters was unable to reach either the father or headteacher.
On Thursday the Borno state governor said the army planned to move into the Sambisa forest, a Boko Haram stronghold, in a bid to rescue the remaining girls.
Previous military attempts to storm the vast forest have met with mixed success, with soldiers making significant in-roads but failing to finish off the Islamist militants after running into bands of well-armed guerrillas, mines and booby traps.
Under Buhari's command, and aided by Nigeria's neighbors, the army has recaptured most territory lost to Boko Haram. But the jihadist group, which last year pledged loyalty to Islamic State, still regularly stages suicide bombings.
Boko Haram captured 276 girls in the Chibok raid but 57 escaped in the melee. The parents of the remaining 219 accused then-President Goodluck Jonathan of not doing enough to find their daughters.
Additional reporting by Camillus Eboh and Alexis Akwagyiram; Editing by Ed Cropley