(BBC) --- Some of the schoolgirls abducted by suspected militant Islamists in northern Nigeria are believed to have been taken to neighbouring states, a local leader has told the BBC.
Pogo Bitrus said there had been "sightings" of gunmen crossing with the girls into Cameroon and Chad.
Some of the girls had been forced to marry the militants, he added.
Mr Bitrus said 230 girls were missing since militants attacked the school in Chibok, Borno state, two weeks ago.
The Islamist group Boko Haram has been blamed for the night-time raid on the school hostel in Chibok town. It has not yet commented on the allegation.
Mr Bitrus, a Chibok community leader, said 43 of the girls had "regained their freedom" after escaping, while 230 were still in captivity. This is a higher number than previous estimates, however he was adamant it was the correct figure.
The students were about to sit their final year exam and so are mostly aged between 16 and 18.
"Some of them have been taken across Lake Chad and some have been ferried across the border into parts of Cameroon," he told the BBC.
Mr Bitrus said there were also reports that the insurgents had married some of the girls.
"We learned that one of the 'grooms' brought his 'wife' to a neighbouring town in Cameroon and kept her there," he told the BBC.
"It's a medieval kind of slavery," he added.
Boko Haram leader Abubakar Shekau first threatened to treat captured women and girls as slaves in a video released in May 2013.
It fuelled concern at the time that the group is adhering to the ancient Islamic belief that women captured during war are slaves with whom their "masters" can have sex, correspondents say.
Mr Bitrus said everyone in the community felt as though their own daughters had been abducted.
Men were "braving it out", but women were "crying and wailing", he said.
"Whether it is my niece or whoever it doesn't matter. We are all one people," Mr Bitrus told the BBC.
"That's why I'm crying now as community leader to alert the world to what's happening so that some pressure would be brought to bear on government to act and ensure the release of these girls."
The government has said the security forces are searching for the girls, but its critics say it is not doing enough.
Boko Haram has staged a wave of attacks in northern Nigeria in recent years, with an estimated 1,500 killed in the violence and subsequent security crackdown this year alone.