World oil prices rose above 64 dollars a barrel Friday amid worries of supply.

New York's main contract, light sweet crude for delivery in May, rose 35 cents to close at 64.26 dollars a barrel.

On London's ICE Futures exchange, the price of Brent North Sea crude for May delivery climbed 24 cents to end at 63.51 dollars a barrel.

The Department of Energy said Wednesday that U.S. commercial crude oil inventories fall unexpectedly in the week ended March 17 while supplies of gasoline and other refined products also declined. It was the first weekly drop in commercial crude oil reserves since early February.

The Italian oil giant ENI warned customers Friday that it might not be able to fulfil some export contracts after an attack on one of the firm's Nigerian pipelines, according to AFP.

A March 17 bomb attack on the Tebidaba to Brass pipeline had cut production in the southern Niger Delta by 75,000 barrels per day, 13,000 of them belonging to ENI's subsidiary Agip.

Nigeria is Africa's leading oil producer and the fifth-biggest source of U.S. oil imports. About one-fourth of the country's daily output is still shut after a series of militant attacks.

The Department of Energy said Wednesday that U.S. commercial crude oil inventories fall unexpectedly in the week ended March 17 while supplies of gasoline and other refined products also declined. It was the first weekly drop in commercial crude oil reserves since early February.

Source: Xinhua