The West Africa coastline recorded a 50% increase in kidnapping of sailors last year, according to a maritime watchdog, even as overall piracy incidents declined worldwide.

The number of sailors kidnapped off West Africa rose to 121 last year from 78 in 2018 in the Gulf of Guinea, says the International Maritime Bureau (IMB) in its annual report.

It represents 90% of global kidnappings reported at sea worldwide.

The gulf is considered among the most dangerous waters in the world. It stretches from Angola in the south to Senegal in the north.

The report said incidents of piracy had declined in 2019 but "vessels remain at risk in several regions, especially the Gulf of Guinea".

"These latest statistics confirm the importance of increased information exchange and coordination between vessels, reporting and response agencies in the Gulf of Guinea region,” said Michael Howlett, director of IMB.