The International Maritime Bureau says pirate attacks have increased sharply worldwide in the past three months, especially in Nigeria and Somalia.

The bureau said Thursday 85 piracy attacks have been reported throughout the world between April and June.

That is double the number of incidents reported in the preceding three months. Forty-one attacks were reported from January through March.

Despite the recent surge in piracy, the overall number of attacks in the first six months of 2007 is in line with the number of attacks in the same period last year (126 in 2007, versus 127 in 2006.)

Maritime officials say the recent rise in piracy is a surprise, as there has been a sustained decrease in piracy during the past three years.

The maritime bureau says Nigeria and Somalia remain high risk areas for ships. Nineteen piracy incidents have been reported off the Nigerian coast, and 17 other attacks occurred off the Somali coast.

Earlier this week, two U.N. agencies issued a joint appeal for coordinated, international action to combat piracy off the coast of Somalia.

In a statement Tuesday, leaders from the International Maritime Organization (IMO) and the World Food Program (WFP) warned that piracy threatens the fragile supply line for assistance to the troubled nation.

Some information for this report was provided by AFP AP.