Oil prices have climbed for a fourth day running and are now hovering near levels not seen since the 1991 Gulf War.

The latest spurt upwards came as chief UN weapons inspector Hans Blix briefed the UN Security Council.

US prices closed on Friday at a new peak of $36.80, close to the $37 mark last seen in 1991.

Prices were also higher in the UK, where the market is measured by a different grade of oil.

The benchmark crude oil contract for April in London stood at $32.5 a barrel, up four cents.

War jitters

Singapore's DBS Bank said "two key geopolitical risks" were boosting oil prices; the threat of war with Iraq and mounting tensions in the Korean Peninsula.

"The US/Iraq war scenario is turning out to be messier than what markets had hoped for," it said in a report.

Oil prices have risen more than 35% since December, fuelled by low fuel stocks in the US, the threat of war in the Middle East and a crippling strike in Venezuela which has slowed oil sales from the world's fifth biggest oil exporter.

"The market has pretty well priced in the worst case scenario but it could go up with the launch of hostilities," said analyst David Thurtell at Commonwealth Bank in Sydney.