Five Somalian pirates drowned and their share of a $3-million US ransom was lost at sea this week, residents and pirates in the Somali port of Harardhere said on Saturday.

Three others in the boat, which sank during a storm on Friday, managed to reach shore after swimming for several hours, according to Daud Nure, himself a pirate but not part of the latest hijacking operation.

Nure said the vessel overturned shortly after the pirates released the Sirius Star, a Saudi-owned oil tanker, following a two-month standoff in the Gulf of Aden.

Abukar Haji, the uncle of one of the dead men, said the deaths were an accident.

"The boat the pirates were travelling in capsized because it was running at high speed because the pirates were afraid of an attack from the warships patrolling around," he said.

The Saudi Arabian oil minister said the crew of the Sirius Star was safe and that the tanker had left Somalian territorial waters and was on its way home.

The Liberian-flagged ship is owned by Vela International Marine Ltd., a subsidiary of Saudi oil company Aramco.

Dozens of pirates were involved in the Nov. 15 hijacking of the oil-laden vessel.

The ransom was delivered on Friday by airdrop, parachuted close to the ship in a waterproof case for the pirates to collect. They were then allowed to make their escape.

The pirate-infested Gulf of Aden, which separates Somalia on the African continent from Yemen, is one of the world's busiest shipping routes.

A new international naval force under U.S. command is set to begin patrolling the area next week to stem the growing problem of pirates.

Somalian pirates are still holding nearly 300 crew members hostage aboard 17 ships. Those vessels  include the weapons-laden Ukrainian cargo ship MV Faina, seized in September.

In the past year alone, pirates from the east African country have carried out 165 attacks. The French military says that number is up from 58 hijackings in 2007.

With files from the Associated Press