KUALA LUMPUR: Heavily armed Somali pirates fired on a Kuwaiti oil tanker near the Arabian Sea on Wednesday in an attempt to hijack the vessel, a global maritime watchdog said.

Noel Choong, head of the International Maritime Bureau piracy reporting centre in Kuala Lumpur, told AFP pirates armed with automatic weapons and rocket-propelled grenades launched the attack from a skiff off Somali waters.

"The Somali pirates chased the tanker and sprayed bullets early Wednesday in a bid to hijack the ship," he said.

"Fortunately, the tanker managed to escape the pirates," Choong said, adding there were no reports of injuries to the crew.

He urged seafarers to be on high alert as pirates were attacking ships on "all fronts."

"Pirates are expanding their areas of attack. They are now operating in the Gulf of Aden, Arabian Sea and in the Indian Ocean," he said.

Somali pirates captured a freighter, bulk carrier and a chemical tanker recently, defying foreign warships patrolling the Gulf of Aden and ending the year with millions in ransom.

The marauding sea bandits' latest catch was the St James Park, a UK-flagged chemical tanker with a crew of 26 from nine different countries, which was seized on Monday.

Since the resumption of pirate attacks following the end of the summer monsoon season three months ago, Somali pirates have abandoned the Gulf of Aden for the wide open seas of the Indian Ocean, venturing as far as the Seychelles and beyond, Choong said.

Despite the increased international military presence off Somalia's coastline -- the longest on the African continent -- pirates have raked in huge ransoms.

Alongside the EU, the United States and other national navies deployed warships off the Somali coast in December 2008 to protect vessels and secure maritime routes in the Gulf of Aden and the Indian Ocean.