Nigerian missing girls: Mothers' 'agony' for daughters

Parents of the schoolgirls who have been abducted in Nigeria have spoken of their pain as they wait for news of their missing daughters.

More than 200 girls were abducted three weeks ago from their school in Borno state by suspected Islamist militants.

President Goodluck Jonathan has admitted that Nigerian security forces do not know where the girls are being held.

The BBC's Will Ross reports from Abuja.