The International Maritime Organization is urging cooperation as piracy spikes in the Gulf of Guinea.

IMO Secretary-General Kitack Lim expressed "deep concern" about the increasing number of incidents in the waters off West Africa, including the fatal attack on the 2,824-teu boxship Mozart (built 2007), in a circular published last week.

"The illicit incidents in the Gulf of Guinea present a serious and immediate threat to the safety and security of crews and vessels operating in the region," the circular said.