Story highlights Child brides will rise from 125M to 310M

UNICEF boss calls each case a tragedy

(CNN) When Fatimetou was 13-years-old she was forced to marry a much older man. She kept running away, but her family kept sending her back.

"I could not look at him," says the girl from Mauritania, in west Africa.

"And then when I saw his face I thought: 'I really hate that man.'"

Her story is not unusual in this part of the world.

Briggite, from the Democratic Republic Congo, was 13 when she gave birth.

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