Athens  - Somali pirates safely released a Greek owned chemical tanker with 19 member crew that was hijacked in September, the Greek Ministry of Merchant Marine said Saturday.

An official from the ministry told Deutsche Presse-Agentur dpa that the ship was released on November 19 that that the cargo of petrol and all 19 crew members, from Georgia, Sri Lanka and Syria, were safe and in tact.

The Somali pirates had hijacked the vessel, NV Genius, under the ownership of Greek shippig company Mareship on September 25 in the Gulf of Aden, near the Horn of Africa, as it was sailing from Romania to the Emirates.

The ship is the latest to be released by pirates after seizing dozens of vessels in recent weeks.

Pirates have reportedly demanded a 25-million-dollar ransom for the Sirius Star carrying 100 million dollars' worth of crude oil, which they seized over the weekend around
830 kilometres south-east of the Kenyan port of Mombasa - way outside the normal piracy danger zones in the Gulf of Aden.

The Sirius Star has been anchored off the Somali port town of Haradhere since Tuesday. However, Islamist insurgents, angry that a ship from a Muslim country has been taken, now say they will act against the pirates.

Some analysts have said that the insurgents battling the government in south and central Somalia have links to the pirates. The pirate groups themselves deny these links, and anecdotal evidence suggests they are using ransom money to fund lavish lifestyles rather than help the insurgents.

Piracy off the Horn of Africa nation has surged in recent months as Somalia descends further into chaos and the ineffectual central government continues to squabble rather than govern.

Another three ships were seized after the Sirius Star was taken. Prior to the latest seizures, the International Maritime Bureau (IMB) said there had been 92 attempts at piracy in the region this year, 36 of them successful.

Around 17 vessels are in the hands of pirates along with over 300 crew.

The surge in piracy has prompted increased patrols by the North Atlantic Treaty Organization, Russia, the US-led coalition forces, India and France along the Somali coast.

The European Union has also authorized a force of between five and seven frigates, which is expected to arrive in the Gulf of Aden early December.

However, the increased naval presence has not deterred the pirates as they pursue huge ransoms.

London-based think tank Chatham house said in October that pirates had received an estimated 30 million dollars in ransoms this year.

Shipping firms and the international community are demanding firmer action against the pirates, and this seems to be slowly coming.

The Indian navy earlier this week destroyed a pirate mothership for the first time. It is expected to take more aggressive action after receiving permission to actively pursue pirates, Indian media reports said Friday.

But shipping companies are beginning to avoid the Gulf of Aden - a busy shipping channel which forms part of the route linking the Indian Ocean with the Mediterranean Sea through the Suez Canal.

Industry analysts say that this will drive up the cost of shipping as companies take the longer route round the Cape of Good Hope. (dpa)