Crude oil prices finished higher Friday as traders remained worried about tight supply amid strong global demand.

On the New York Mercantile Exchange, oil futures for April delivery climbed 32 cents to end at 56.72 dollars a barrel, topping the previous closing high of 56.46 dollars a barrel.

Meanwhile, on London's International Petroleum Exchange the April Brent crude-futures contract added 53 cents to settle at 55.59 dollars per barrel.

The Organization of Petroleum Exporting Countries (OPEC) decided to add 500,000 barrels of oil a day to its previous targets, but the initiative failed to calm the markets due to widespread concerns about the oil cartel's limited ability to quickly pump more barrels to the market.

"It still looks like we haven't found a top yet," said Tom Bentz, a broker at BNP Paribas Commodity Futures in New York.

After the feverish rally in recent weeks, oil prices went up 15dollars since the start of the year. Oil futures were 50 percent higher than a year ago.

Source: Xinhua