A Nigerian plane taking part in an exercise aimed at testing disaster response operations has crashed in the southern oil city of Port Harcourt.

The air force plane - carrying dozens of officials - skidded off the runway as it was landing at the city's international airport.

Emergency workers on the ground who had been preparing to stage a mock rescue had to deal with a real accident.

The passengers and crew escaped with only minor injuries.

"No life was lost but the aircraft was severely damaged," police spokeswoman Rita Inoma-Abbey was quoted as saying by Reuters news agency.