NEW YORK (CNN/Money) - Crude oil prices rose above $30 a barrel Tuesday, hitting a 18-month high, amid worries that a war in Iraq will disrupt the supply.

At the New York Mercantile Exchange, crude oil for September delivery rose as high as $30.32, the highest price since February 2001, before closing at $30.11, up 27 cents on the day.

The Bush administration has been considering an attack on the Middle Eastern nation, which is thought to be harboring weapons of mass destruction.

"Without the threat of war priced into oil, crude would be trading in the low $20s," said Jack Aydin, oil analyst with McDonald Investments.

The gain in oil prices comes despite a comment by Kuwait's oil minister that the Organization of Petroleum Exporting Countries was ready to increase crude supplies to world markets if the United States decided to go ahead with a military strike on Iraq.

Most oil stocks fell, including Exxon-Mobil (XOM: Research, Estimates), the No 1 producer.

"Oil seems to be disappearing from the marketplace and my theory is that the U.S. is adding to its strategic oil reserves with the intention of releasing it during an attack on Iraq," Phil Flynn, energy analyst with Alaron.com, told CNNfn's MoneyMorning.

The White House denied Monday that it is stockpiling oil for action against Iraq. "The reserves are meant for times of emergency," White House press secretary Ari Fleischer said, adding that President Bush had no plans to tap into the nation's emergency reserves.

Adding to the tensions in the Middle East, U.S. and British fighter jets bombed an air defense command and control facility about 120 miles southeast of Baghdad early Tuesday morning, according to the U.S. Central Command.

It was the third Western raid against Iraqi targets within a week, following a strike against a mobile radar unit Saturday and strikes by U.S. and British planes against targets in southern Iraq last Wednesday.

--from staff and wire reports