NAIROBI, Kenya -- A small gang of Somali pirates fired on an approaching ship, hoping their midnight attack would bring them millions in ransom. The ragtag bandits, though, had taken on far more than they could handle: a US Navy warship.

The USS Nicholas, a guided-missile frigate, was tracking the pirates when they opened fire early yesterday in the Indian Ocean, military officials said. The Nicholas returned fire and disabled the skiff.

Navy personnel later boarded and detained three suspects. Two more bandits were found on a nearby boat.

It was not the first attack against a Navy ship, but it underscored the fact that most pirates aren't terribly sophisticated, said Roger Middleton, a piracy expert at the British think tank Chatham House.

"If you think of the kind of young men who are doing this, they go out into the middle of the ocean in a tiny boat," said Middleton. "Perhaps they just see a big ship they think is worth a lot of money."

International forces have stepped up enforcement of the waters off East Africa in an effort to thwart a growing pirate trade. Yesterday's attack took place between the coast of Kenya and the island nation of Seychelles, said Navy spokesman Lt. Patrick Foughty.

French and Dutch naval ships also have been attacked by pirates.

The US Africa Command said the five pirates seized yesterday would remain in custody on board the frigate for now.

Experts say piracy will continue to be a problem until an effective government is established on Somalia's lawless shores. The country has not had a functioning government for 19 years.