LAGOS, Nigeria (AP) — Three weeks after Islamic militants kidnapped more than 300 girls from a school dormitory in Nigeria, 276 remain missing.

An intermediary who is in communication with their captors says at least two of the girls have died of snakebite and about 20 are ill.

The extremist group Boko Haram (BOH'-koh hah-RAHM') says it has the girls and is threatening to sell them. Fifty students managed to escape.

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