NAIROBI, April 30 (Xinhua) -- A French warship has destroyed a pirate mother ship, some 480 nautical miles east of the Somali coast, EU Naval Force said on Friday.

Naval Force spokesman John Harbour said the French warship Nivose on Thursday boarded and searched the vessels but the pirates were found to have disposed of pirate paraphernalia. "The EU NAVFOR warship Nivose found stopped and searched a mother ship and two supporting skiffs, some 480 nautical miles east of the Somali Coast. The 11 Somali crew of these vessels were taken on board the Nivose, as were the two attack skiffs and the mother skiff was sunk," Harbour said in a statement.

He said the EU Naval Force will continue with its aggressive stance against piracy and the intention to interdict and disrupt pirate activity.

Harbour said over 40 pirate action groups have been disrupted in the last two months showing that the new strategy is working.

According to the world's anti-piracy organization, the International Maritime Bureau, Somali pirates attacked ships 217 times in 2009, up from 111 attacks in 2008.

Crews have been successfully repelling more attacks, making it harder for pirates to capture ships and earn multi-million-dollar ransoms.

But the pirates have responded more violently. The IBM says only seven ships were fired upon worldwide in 2004, whereas 114 ships were fired upon last year off the Somali coast alone.

Many ship owners are investing in physical defences like stringing razor wire and adding fire hoses that can hit attackers with streams of high-pressure water. Some ships are even having electric fence-style systems installed.