The weekly average oil price of the Organization of Petroleum Exporting Countries (OPEC) continued to increase last week, rising to 123.74 U.S. dollars per barrel, the Vienna-based cartel said Monday. OPEC oil prices have risen for six consecutive weeks since mid-February, partly due to volatility in Iran and much of the Middle East. It is said one of the major topics discussed between British Prime Minister David Cameron and U.S. President Barack Obama during a recent meeting at the White House was the need to release strategic petroleum reserves to stabilize oil prices. Although the White House later denied this, it highlighted concerns over the current trend of increasing oil prices. The International Energy Agency said the global economic outlook this year is expected to be weak. Despite U.S. crude oil inventories rising by 1.75 million barrels in March, a strong U.S. dollar, and no sign of a supply shortage in crude and refined oil market, international oil prices have continued rising. Last week, daily oil prices reached a record high of 124.59 dollars a barrel. \"The market is inconsistent with the oil price trend, which is puzzling,\" said Tony Rosado, an analyst at Global Markets.