Nigeria's piracy problem is driving up shipping costs, the country's shipowners association has said.

Insurance for vessels and seafarers has rocketed nearly 60%, the Nigerian Shipowners’ Association (NISA) told Business Day.

“Nigeria is categorised as a war-risk zone. Our insurance is more than three times the insurance of every other place in the world," said NISA president Aminu Umar.

"The incidence has been on the rise, especially on kidnapping of the crew, which is making the shipping business very difficult.