A spike in pirate attacks off Benin has forced dozens of ships to steer clear of the West African state's waters, the head of the country's navy said of a trend that is likely to hit the port-heavy tax revenues and hurt economic growth, news agencies report. The tiny nation has been hit by a series of attacks on ships in its waters in recent weeks, forcing London's maritime insurance market to add Benin to a list of areas deemed high risk, Reuters reported. "Dozens of ships are already fleeing our shores due to fears of these pirates," Chief of Staff of the Navy Maxime Ahoyo said on Thursday without giving a precise figure. Ahoyo said ships in the country's waters were leaving while those due to enter them were also staying away. Benin, which exports cotton and is an entry port for land-locked countries such as Niger, Chad and Burkina Faso, collects about 100 billion CFA francs ($218 million), or some 40 percent of government receipts, from port activities each year. Joseph Ahahanzo, managing director of the port of Cotonou, which is managed by the Bollore Group , warned several weeks ago that 80-85 percent of customs duties were collected in the country's ports and business had already been hit. Piracy in the Gulf of Guinea, which stretches through a dozen countries from Guinea to Angola, is not comparable to the waters off Somalia, but analysts warn that it is set to increase unless countries beef up weak navies. -- SPA