LAGOS, Nigeria — An official says the mother of Nigeria's finance minister has been released after being abducted by kidnappers.

Paul Nwabuikwu, a spokesman for Nigeria's finance ministry, said the mother of Minister Ngozi Okonjo-Iweala was released Friday morning. He offered no other details.

Okonjo-Iweala is a respected economist who was nominated earlier this year to become World Bank chief before losing to Jim Yong Kim, who was nominated by the United States.

The West African country has seen a spate of kidnappings and growing sectarian violence.

Experts say kidnappers who once targeted mainly expatriate oil workers have shifted their focus to wealthy Nigerian families in recent years. Nigeria's oil-rich delta is a kidnapping hotspot, but many cases go unreported.