Oil prices edged down on Friday morning as investors weighed Middle East risks and possible US steps to ease restrictions on the world's "shadow fleet" of tankers.

Brent crude futures fell 41 cents, or 0.39%, to $105.51 a barrel by 0012 GMT, while US West Texas Intermediate crude futures CLc1 were down 54 cents, or 0.55%, to $97.43.

WTI settled up more than 3% on Thursday after a large US crude stock draw helped support prices, while Brent crude was little changed.

The International Energy Agency agreed on Thursday to release over 20 million barrels of diesel to the market and any oil remaining from a record release of emergency reserves pledged in March to boost supply and cool soaring prices.

During the previous trading session, oil prices rose overnight in a sign that "investors were dissatisfied with these measures," Haitong Futures in a note on Friday.

"What would really cool the oil market is an easing of tensions in the Middle East."

The Trump administration is considering lifting sanctions on some so-called shadow fleet vessels that have transported oil and petroleum products from countries including Russia, Iran and Venezuela, in an effort to reduce record-high global freight rates, a US official said on Wednesday.

The discussions come days after President Donald Trump temporarily lifted sanctions on Russian diesel fuel, a move met with a torrent of criticism from Ukrainian President Volodymyr Zelenskiy, European countries and some of Trump's fellow Republicans in the US Senate.

Meanwhile, escalating conflict between Saudi Arabia and Yemen's Houthis and renewed attacks on ships in the region supported prices.

Attacks around the waterway have surged over the past 10 days, with Iran saying it was stepping up strikes in response to the US blockade of its ports and tougher sanctions introduced last month.

The Houthis fired missiles at the presidential palace complex in the southern city of Aden on Thursday, killing two guards, while the Saudi-led coalition in Yemen detailed dozens of attacks on Saudi infrastructure in the escalating conflict.