LAGOS, Nigeria (AP) — Nigerian police say kidnappers have abducted the finance minister's mother from her home in the West African nation's oil-rich delta.

National police spokesman Frank Mba told The Associated Press that Kamene Okonjo, mother of Finance Minister Ngozi Okonjo-Iweala, was kidnapped Sunday afternoon in Delta state.

He says "no stone would be left unturned" to secure her freedom.

Finance Ministry spokesman Paul Nwabuikwu said in a statement Sunday the minister had received threats in the past.

The abduction occurred in an oil-rich region where kidnappings that once affected mainly expatriate workers have increasingly targeted middle-class and elite Nigerian families.