In Picture: Principal of the Chibok Girls Secondary School

Here is the face of the principal of the Chibok Girls Secondary School, Borno state, North east Nigeria, where 276 girls were kidnapped by Boko Haram militants on 14 April.

The kidnap has stirred international concerns about the state of insecurity in Nigeria.

Of the 276 girls taken away, 223 are still with Boko Haram militants, with reports that the girls had been married off to them for as little as N2,000, about $12.