Gunmen in Nigeria have kidnapped the elder brother of Nigerian and Everton football star Joseph Yobo, police say.

Norum Yobo was seized at a hotel in Port Harcourt, a spokeswoman said.

No group has yet claimed responsibility and no ransom has been demanded.

Everton football club said it would do all it could to help Joseph Yobo, who is on holiday in Lagos.

Kidnappings, frequent in the oil-rich Niger Delta region of the country, have mostly ended with a ransom payment.