Better equipped Somali pirates operating deep at sea threaten oil tankers in key waterways, and more naval firepower is 'desperately needed' to combat the growing risk, shipping groups warned.

Seaborne gangs are making tens of millions of dollars in ransoms, and despite successful efforts to quell attacks in the Gulf of Aden, international navies have struggled to contain piracy in the Indian Ocean owing to the vast distances involved.

Shipping associations Bimco, the International Chamber of Shipping, Intercargo and Intertanko said in a joint statement on Tuesday the situation had 'changed radically' in recent weeks due to new pirate tactics, which included heavier firepower.

'They make greater use of so-called mother ships, some of them large hijacked vessels, which has vastly expanded their range of operation to encompass much of the Arabian Sea between the Gulf of Aden, Somalia and India,' the statement said.

'Over 40 per cent of the world's seaborne oil supply now passes through waters at high risk from pirate attack.'

The groups urged immediate action by governments 'before these tactics make trading in the area almost impossible'.

They added, 'We call on the world's governments to note the extent to which additional international naval assets in this region are desperately needed.'

Responding to the growing threat, London's marine insurance market last month expanded the stretch of waterways deemed high risk from seaborne raiders to include the Gulf of Oman and a wider stretch of the Indian Ocean.

The growing menace has also meant that grain shipments and are being diverted around Africa, increasing journey times and potentially lifting insurance costs at a time of unrest over food prices. There is also rising frustration among seafarers who find themselves in the firing line.

Global pirate attacks hit a seven-year high in 2010 and a record number of crew were taken hostage, with Somali pirates accounting for 49 of the 52 ships seized, the International Maritime Bureau watchdog said this month.

Escalation likely

Last week South Korean troops stormed a hijacked chemical ship in the Arabian Sea, killing eight pirates and capturing five after they rescued all of the crew members. The vessel's captain was shot by pirates during the rescue.

Malaysian navy commandos last week foiled an attempted hijacking of a Malaysian-owned ship in the Gulf of Aden, freeing crew members and detaining seven pirates.

'We respect and value the bravery of the special operations teams involved and the risks they took,' the statement said.

In a sign of escalation, Somali pirates have threatened to kill any South Korean seaman captured in future in revenge for the eight pirates killed.

John Drake, a senior risk consultant with security firm AKE Ltd., said attacks on ships were likely to increase.

'AKE believes the problem will get worse. The pirates have more buying power, so they can purchase more weaponry, navigational equipment and skiffs,' he said. 'They can also bribe more officials and hire more men, many of whom will be attracted to the industry by its increasing success.' – Reuters