ABUJA - A schoolgirl who was among more than 200 kidnapped by Boko Haram in 2014 refused to be part of a release deal because she had married a militant fighter, Nigeria's government said on Tuesday.

Presidency spokesman Garba Shehu said the militants had agreed to the release of 83 of the teenagers, who were abducted from their school in Chibok in April 2014. But Shehu told the local Channels television station: "One said, 'No, I have a husband. I'm happy where I am'. And then 82 came back." The 82 were released on Saturday following months of talks and the exchange of a number of suspected militants held in government custody. Twenty-one of their classmates were freed in October last year; three had previously been found or escaped. Talks are understood to have started to free all or some of the remaining 113. Shehu said the government was working to verify the identities of the 82, so they can be reunited with their families as soon as possible. A list of the girls' names was published on Sunday evening and photographs of them have been sent to the remote town of Chibok for cross-checking.

"When we had the first 21, because of similarities in names, more than two, three sets of parents came to Abuja. So, we don't want to create that confusion," he said.

"When they get the pictures, they see them and verify, then they come on board to Abuja to see their daughters."

Aisha Yesufu, coordinator of the #BringBackOurGirls pressure group, told AFP: "We have to reach out to the parents and ensure that we match the parents and the daughters.

"We are still working on it."

Nigeria's government has come under fire for the length of time it has taken to reunite the former hostages with their families.

In December, families complained that the girls were blocked from celebrating Christmas with them.

Amnesty International said on Saturday that holding the released girls in lengthy detention and for security screening "can only add to their suffering and plight".

Shehu said he hoped the verification process would be concluded soon and pledged: "The government will not stop any parents from immediately establishing contacts with their daughters."