Meanwhile, the tensions between Washington and Beijing is scaring hedge funds away from an increasingly volatile oil market, according to Bloomberg, with money managers' total positions in the USA benchmark and Brent having slid to the lowest since 2016.
Beijing, however, agreed not to increase purchases of Iran's crude, the officials, who spoke on condition of anonymity told Bloomberg on Friday.
WTI settled down 47 cents to $68.49 per barrel, and Brent fell 24 cents to $73.21 per barrel, causing Jim Ritterbusch, president of Ritterbusch & Associates, to remark, "It's a jittery feel here, as long as we have Iranian sanctions uncertainty and tariff uncertainty, and it doesn't take much to spark a significant swing one way or the other".
Iran has been furious over U.S. President Donald Trump's decision to pull out of an worldwide agreement on Iran's nuclear program and re-impose sanctions on Tehran.
In return, United Nations-approved sanctions were lifted, and Iran was allowed to resume trading oil and gas on the global market.
Washington imposed a series of additional sanctions on Iranian entities and individuals, as well as foreign companies in Iran, squeezing Iran economically.
On Sunday, Iran received five more ATR turboprop airplanes only a day before the return of United States sanctions that have already torpedoed the country's plane purchases with other major providers.
"At 9pm [15:30 GMT on Friday] they attacked the school and tried to break the doors down and burn things", the Fars News Agency quoted the head of the school in the town of Ishtehad, Hojatoleslam Hindiani, as saying.
Iran is also said to have started to offer India cargo insurance and tankers operated by Iranian companies as some Indian insurers have refused to cover oil cargoes from Iran in the face of the returning USA sanctions on Tehran.
Washington made a decision to reimpose sanctions on Iran upon its withdrawal, accusing it of posing a security threat, and has told countries they must halt all imports of Iranian oil from November 4 or face United States financial measures. While the Trump administration has said it wants to cut Iranian oil exports to zero by November 4, most analysts viewed that target as unlikely.
"China will continue to cooperate with Iran adhering to its worldwide obligations".
State refiners that had cut imports from Iran in 2017/18 due to a dispute over development rights of a giant gas field, have tied up significantly higher volumes for this fiscal year that began in April, drawn to the discounts offered by Iran.
Last month around 35 percent of Iranian oil exports went to China.