The Organization of Petroleum Exporting Countries (OPEC)'s weekly average crude oil prices stood at 57.85 U.S. dollars per barrel, up 0.35 dollars from the previous week, the cartel's secretariat said Monday.

Ahead of the U.S. driving season, U.S. market data released last week showed an unexpected decline in crude oil stocks and gasoline supplies, which sent the crude oil daily prices to as high as 58.64 dollars Thursday.

In the meantime, concerns and fears about supply interruptions in Iran and a possible widening of sanctions over its nuclear programme were another main factor pushing the prices strongly up.

However, in the last trading day, crude oil prices slipped down slightly, mainly due to forecasts of warm temperatures in the U.S.

The U.S. National Weather Service has forecast above-normal temperatures in the coming two weeks in most parts of the Midwest and Northeast America, which are also the largest heating oil demand areas.

Meanwhile, concerning OPEC's general meeting this week, some market analysts said the oil cartel was widely expected to keep its oil-production level unchanged.

OPEC President Mohammed al-Hamli said last week in Dubai that the current global oil market was good and expressed satisfaction with the previous production cuts by its members.

Source: Xinhua