Oil prices spiked to a record US$117.40 a barrel after a Japanese oil tanker was attacked off the east coast of Yemen.

The 150,000-ton tanker Takayama was attacked about 440 kilometres (270 miles) off the Yemen coast in the Gulf of Aden while it was heading for Saudi Arabia, its Japanese operator, Nippon Yusen KK, said in a statement posted on its website.

None of the ship's 23 crew members was injured but several kilolitres (hundreds of gallons) of fuel leaked before a 2-centimetre (1-inch) hole in the tanker's stern was repaired, the company said.

Kyodo News agency reported that the Japanese tanker was fired on by a rocket launcher from a small boat.

Pushing up prices

News of the attack pushed crude oil futures higher into record territory.

Light, sweet crude for May delivery reached US$117.40 a barrel but fell back to US$116.88 by midday in Europe, up 19 cents from Friday's closing price.

In London, Brent crude futures for June rose 21 cents to US$114.13 a barrel on the ICE Futures exchange.

"There's clearly some geopolitical tension in the market," said Mark Pervan, senior commodity strategist at the ANZ Bank in Melbourne, Australia. "This will die down, but the market is pretty jittery at the moment."

Two more attacks

Adding to the worries were claims Monday from the main militant group in Nigeria's restive south that it had launched two more attacks on oil pipelines in the region. There was no immediate confirmation.

Last Friday, oil prices rose to touch US$117 for the first time after an attack on a Royal Dutch Shell PLC pipeline by the Movement for the Emancipation of the Niger Delta.

Shell confirmed a pipeline leak that it said appeared to have been caused by explosives. It said it had isolated the line for repairs and that a small quantity of production had been shut.