Oil prices rose more by than $1 to above $70 a barrel this evening after a Nigerian group shut down one of Royal Dutch Shell's pipelines, raising concerns about supplies from the region.
US crude rose $1.43 to $70.10 a barrel, while London Brent crude rose $1.59 to $69.92.
In the latest in a string of attacks in Nigeria, Africa's biggest oil producer, the Movement for the Emancipation of the Niger Delta (MEND), said it had sabotaged the Billie-Krakama pipeline in Rivers State, which supplies one of the country's main export terminals.
Attacks by MEND have forced foreign oil companies, including US oil major Chevron and Italy's Agip, to shut at least 133,000 barrels per day of oil production in the last month.
Shell said it had shut down one of its pipeline junction points today but declined to say whether any oil production had been affected.
Oil prices also received a boost from a rebound in petrol futures ahead of the July 4 holiday - typically one of the busiest US driving holidays of the year.
Crude prices have more than doubled since the lows near $30 a barrel plumbed last winter, on hopes for an economic recovery.
