Crude oil futures inched higher on Friday, supported by a surprise drop in U.S. oil inventories and simmering Middle East tensions, but prices were headed for their biggest weekly loss in more than a month on worries of lower demand.

After rising for the first time in five days a day earlier, crude futures resumed their descent on Friday, with prices of the U.S.-traded benchmark briefly breaking below $70 a barrel overnight.

Oil futures fell on Friday, declining more than 7% on the week after data showed China's economic growth slowed and investors digested a mixed Middle East outlook. Brent crude futures fell $1.39, or 1.