A woman leading protests over the abduction of more than 200 girls in Nigeria has been detained on the orders of the president's wife, activists say.
Naomi Mutah took part in a meeting called by First Lady Patience Jonathan and was then taken to a police station, they say.
Mrs Jonathan reportedly felt slighted that the mothers of the abducted girls had sent Ms Mutah to the meeting.
Analysts say Mrs Jonathan is a politically powerful figure.
Ms Mutah, a representative of the Chibok community where the girls were seized from their school more than two weeks ago, last week organised a protest in the capital, Abuja.