The Spanish officers will form part of a group of team of international experts working together to help find the missing girls, Spain's El País newspaper reported on Thursday.

They will join experts from the UK, France, Israel and China in the search for the teenage girls kidnapped from a school in northern Nigeria on April 14th.

The chief aim of the group to be based in the Spanish embassy in the Nigerian capital of Abuja, is to stop the girls being sold into slavery, the daily reported.  

The police officers will also join the 80 military personnel deployed to Chad by the US on Wednesday.

In a letter to congress, US President Barack Obama said the personnel would stay in Chad until their support in ending the abduction nightmare that has outraged the world “is no longer required”.

“These personnel will support the operation of intelligence, surveillance and reconnaissance aircraft for missions over northern Nigeria and the surrounding area,” Mr Obama said.

The troops mark a significant boost to an existing US military effort which includes the use of surveillance drones as well as manned aircraft over Nigeria.

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