The price of Brent crude oil hit $101 a barrel in London at one point this evening for the first time since October 2008, as traders worried about unrest in Egypt.
There are fears that the unrest in Egypt could disrupt the flow of oil through the Suez Canal on its way to the West.
About one million barrels of oil pass each day through the Suez Canal, a key transit route for shipments from the Persian Gulf region.
Brent crude oil later stood at $100.83 a barrel, up $1.43 from Friday's closing level. US crude gained $2.10 to $91.44.
Danish shipping and oil group Moeller-Maersk said it was suspending activities in Egypt, amid growing fears over the unrest rocking the country, but said ships would continue sailing the Suez canal.
The deputy head of the International Energy Agency, Richard Jones, warned that political unrest in North Africa and the Middle East was a 'key' uncertainty hanging over oil markets.
OPEC secretary-general Abdalla Salem El-Badri warned that 'there could be a real shortage' of crude oil passing through the Suez. 'If we see a real shortage, we will need to act,' he said on the sidelines of an oil conference in London.
However, El-Badri stressed that 'the market is well supplied' with strong inventories and 'demand is less than last year' at this time.
The OPEC chief added that he saw no need for an emergency production meeting ahead of the next scheduled gathering in Vienna in June. The Organisation of Petroleum Exporting Counties pumps about 40% of the world's oil, with the bulk coming from member Saudi Arabia.
