Oil prices fell over 1% after the US Federal Reserve raised interest rates and concerns were raised over a weak global economy that could dampen energy demand. Brent crude futures dropped 1.1% to $71.57 a barrel and US West Texas Intermediate crude fell 1.5% to $67.60. Both Brent and WTI have declined more than 10% since the start of the week. Investors are looking to see how the European Central Bank will respond after it announced it would raise rates for the seventh consecutive time.