Boko Haram leader Abubakar Shekau sent a video obtained by the AFP news agency, in which he said for the first time that his group had abducted the Chibok School girls three weeks ago.
God instructed me'
In the video, Abubakar Shekau said the girls should not have been in school in the first place, but rather should get married.
"God instructed me to sell them, they are his properties and I will carry out his instructions," he said.
However, BBC Hausa Service editor Mansur Liman points out that the Boko Haram leader did not state the number of girls abducted, nor where they were taken or are now.
Recall that over 200 girls, aged between 16-18 were taken from their boarding school in Chibok, in the northern state of Borno, on the night of 14 April.
The Associated Press news agency says it is unclear whether the video was made before or after reports last week that some of the girls had been forced to marry their abductors, who paid a nominal bride price of $12 (£7).