Oil prices fell Monday as traders weighed a planned release of emergency oil and diesel stocks by the Group of Seven countries against renewed attacks around the Strait of Hormuz and persistent Middle East supply risks.

December Brent crude futures fell 0.7% to $101.59 a barrel, while December West Texas Intermediate futures dropped 1% to $88.54 a barrel.

The G-7 countries agreed Friday to implement a coordinated release through the International Energy Agency of 100 million barrels of crude oil and fuel over four months, including a substantial diesel release in the first 20 days. The group also pledged not to restrict energy exports between member countries.

The IEA said around 325 million barrels of the 400 million barrels pledged under its collective action announced in March have so far been released. While Middle East crude exports have recovered significantly, refined-product flows remain severely constrained, particularly diesel, the agency said.

A staggered release of European fuel stocks could help ease pressure through the winter, but any effect on prices may be short-lived because global markets remain tight and there is little clarity over when Middle Eastern and Russian supplies will normalize, Eleanor Budds at S&P Global Energy CERA said.

Meanwhile, seven members of the Organization of the Petroleum Exporting Countries and its allies, including Saudi Arabia and Russia, agreed Sunday to keep production levels steady in November.

OPEC's Joint Ministerial Monitoring Committee separately expressed concern over attacks on energy infrastructure and disruptions to international maritime routes, saying they threaten supply availability and increase market volatility.

Shipping risks around the Strait of Hormuz have increased again. U.K. Maritime Trade Operations said Sunday that a tanker in the strait was struck by an unknown projectile, damaging its engine room. The crew was reported safe and no environmental impact was reported.

The latest attack came amid a renewed wave of incidents threatening the recent recovery in Middle East crude exports. Seven vessel attacks have been reported around the strait since Sept. 28, The Wall Street Journal reported. Gulf producers had pushed crude shipments back toward prewar levels using shuttle tankers and alternative export routes.