On Monday, at the closing of the London Stock Exchange, a barrel of European Brent oil was worth $94.55, losing 3.7 percent compared to the price at the end of the previous session, writes Gazeta Wyborcza.
And on the New York Stock Exchange, a barrel of American WTI oil was worth 88.77 dollars, having fallen by 3.6 percent.
During the first session of this week, oil prices on both exchanges fell by as much as 5%.
Oil prices last week eased fears of a global recession.
Now investors have been spooked by news about the poor state of the Chinese economy.
China's National Bureau of Statistics announced on Monday that industrial production rose 3.8 percent in July.
On an annual basis, this is 0.1 percentage point less than in June.
And consumer spending increased by 2.7 percent compared to the same period last year.
This means a further slowdown in the Chinese economy and a growing fear of Chinese spending.
It is mainly related to the credit crisis in the construction market.
After several years of boom, Chinese developers began to go bankrupt under the burden of debts, causing financial problems for construction companies and their partners as well.