LAGOS (AFP) - US experts have arrived in Nigeria to help rescue more than 200 schoolgirls being held hostage by Boko Haram Islamists, an embassy spokeswoman told AFP on Friday.

"They are here...the team is on the ground," Rhonda Ferguson-Augustus said, without specifying the precise make-up of the group. US officials have previously said Washington would send military personnel as well as specialists from the Justice Department and the FBI.