The situation in Iraq continues to concern oil traders (Agencies)

Oil prices fell sharply on Thursday, falling back from recent highs to their lowest levels in more than a month.

In New York a barrel of US light crude ended down $2.03 to $48.85, the first time it has finished under $49 a barrel since late September.

While in London, Brent crude closed down $1.61 to $45.95.

Analysts said rising crude stockpiles in the US were easing prices, but others warned that ongoing violence in Iraq could easily reverse the falls.

Another possible future supply pressure is the continuing threat of a strike in Nigeria, Africa's largest oil producer.

"(US) Oil inventories should rise over the next six to nine months, and this should eventually ease the extreme tightness in today's oil markets," said Adam Sieminski of Deutsche Bank.

Mr Sieminski said other factors that should help prices to fall were weakening global oil demand, and rising supplies both from members of the main OPEC oil producers group, and other oil exporting nations.

OPEC has recently lifted production of oil above 30 million barrels per day to meet booming oil demand.

This supply surge has helped rebuild U.S. crude stocks, which have risen 10 million barrels in the last two weeks.

Yet other oil analysts, such as Venezuela's energy minister Rafael Ramirez, take an opposing view, and warn that oil prices have yet to peak.

"We see the market as unstable," Mr Ramirez said.

"US policy in the Middle East does not help stability in the petroleum market. It creates instability."

Global oil prices have increased by 60% since the start of 2004 due to both supply and demand pressures, such as China's fast growing economy.

(Agencies)

inventory : draw a line or lines underneath to call attention to（强调）

booming: very lively and profitable（急速发展的）