Kenya is preparing to counter a possible oil slick from a Saudi super-tanker seized by Somali pirates should efforts to free the vessel and its two million barrels of crude go awry, officials said Tuesday.

Five days after the Sirius Star's capture on November 15, Kenyan maritime authorities carried out mock operations and readied teams for a possible oil spill, said Captain Geoffrey Namadoa, pollution control officer with the Kenya Ports Authority (KPA).

"This was to sensitise our teams... to be alert if we are required to move north and to keep our equipment ready," Namadoa told AFP.

The response team included the KPA, the Kenyan navy, oil firms and maritime police from Mombasa, a key port on the Indian Ocean coast through which much of eastern and central African trade transits.

A possible oil spill would also damage Kenya's marine parks along its coast that stretches to southern Somalia, Namadoa said, adding that another exercise is planned for this week.

He said the biggest concerns are the marine national parks and the beaches for the tourists.

Tensions were high at the weekend between the pirates and hardline Islamist Shebab militia who threatened to attack the hijackers and positioned fighters around Somalia's coastal village of Harardhere, off which the vessel is anchored.

The international community has also been rushing naval ships to the region in a bid to combat piracy, vowing tough action against a surge in attacks which is threatening major disruptions in international trade.

"We have a plan should there be an oil spill," said Captain Dave Muli, search and rescue manager with the Kenya Maritime Authority.

Muli expalined that in the event of an oil spill "it will be big and spread over a wide area as far east of the Gulf, west coast of India and the east coast of Africa."

Tourism is a key source of income for Kenya, which is renowned for its white sand beaches and high-end resorts.