Armed rebels who recently ended an "oil war" in Nigeria's oil-rich Delta region told AFP on Sunday they have freed 19 hostages abducted by pirates.

"The Nigerian hostages rescued from pirates by the Movement for the Emancipation of the Niger Delta have been released in Rivers state," Mend said in a statement to the media.

But as a result of security concerns in the area where the rescued group was being held, none of the hostages had been yet allowed to leave, the group said.

"Due to the location where the expatriates were kept for their safety, they cannot be released at this time because of security concerns."

AFP