'Used and dehumanized': Dozens of boys found chained in Nigeria

More than 300 boys and men...

Many in chains and bearing scars from beatings, have been rescued in Nigeria.

Police said the boys were freed in a raid on a building that purported to be an Islamic school.

Most of the freed captives seen by a Reuters reporter in the city of Kaduna were children, aged between five and late teens.

It's thought some had come from neighboring countries.

While local media said others had been left by their parents in what they believed to be an Islamic school or "rehabilitation center".

The police added that seven people who said they were teachers at the school had been arrested in Thursday's (September 26) raid.

(SOUNDBITE) (English) POLICE COMMISSIONER, KADUNA STATE, ALI JANGA, SAYING:

''This place is neither a rehab or an Islamic school because you can see it for yourselves. Small children, some of them brought from our neighboring countries like Burkina Faso, Mali, Ghana and the rest. And the children gathered here are from all over the country, across all over the country, some of them were even chained. They were used, dehumanized, you can see it yourself.''

It was not clear how long the captives had been held there.

Police said the children have been moved to a temporary camp while attempts are being made to find their parents.