Crude oil fell in a volatile session on Wednesday, caught between rising attacks by Iran on vessels in the Strait of Hormuz and the continued resilience of Middle Eastern oil shipments.

London copper edged higher as a strike at a Chilean mine deepened supply concerns, though a stronger dollar and a broad pullback in risk assets capped gains. Spot gold also declined as the dollar strengthened.

Crude Oil: Brent Slips as Middle East Flows Hold Up but Hormuz Vessel Attacks Mount

Crude fell in a choppy session, with increasing Iranian attacks on ships in the Strait of Hormuz on one side and still-resilient Middle Eastern oil transportation volumes on the other. Brent crude settled slightly lower near $100 a barrel, while WTI dropped 1.3% to around $88 a barrel.

Although oil shipments through the Strait of Hormuz have increased in recent weeks, the U.K. Maritime Trade Operations office said at least nine attacks have occurred in the waterway so far this month. That already amounts to half the combined total reported for the Strait of Hormuz and the Persian Gulf in September. After the news, oil prices edged higher in post-settlement trading. The report cited by The Atlantic, which quoted two government officials, said the White House has asked the Pentagon to draw up strike options against Iran that could be carried out before the U.S. midterm elections. That reporting runs counter to the prevailing market view that President Donald Trump would avoid conflict before the elections to keep energy costs from rising, since the cost of living is a key voter concern.

Previous rounds of Iranian attacks in the Strait of Hormuz had reduced oil shipments, though higher volumes in the following days typically offset those declines. Shell CEO Wael Sawan said at a forum this week that Middle Eastern oil transportation has recovered to about 80% of pre-conflict levels. Even so, the volume of refined products shipped out of the region remains far below normal. European diesel futures rose as much as 6.8% on Wednesday, with the Iran conflict and Ukrainian attacks on Russian refineries together tightening market supply.

"In my view, the market currently lacks clear direction," said Ole Sloth Hansen, head of commodity strategy at Saxo Bank. "Middle Eastern supply, especially crude, has recovered strongly. But because Iran is not part of that increase, the risk of attacks is rising."

Traders also had to digest mixed U.S. inventory data. Energy Information Administration figures showed crude stockpiles fell by 3.2 million barrels last week, even as inventories at the key Cushing, Oklahoma, storage hub rose slightly for a third straight week. Total crude and refined product exports jumped to the highest level since late May, but a simultaneous surge in imports offset that bullish factor.

Traders are also watching the weather. The first Atlantic hurricane of the season is expected to reach the U.S. Gulf Coast on Friday, potentially bringing damaging winds, flooding and disruptions to energy production.

WTI November futures fell 1.3% to $88.28 a barrel; Brent December futures fell 0.4% to settle at $100.20 a barrel.

Copper Edges Higher as Chile Mine Strike Deepens Supply Concerns

London copper edged up as a strike at a Chilean mine deepened market concerns about supply. However, a stronger dollar and a broad retreat in risk assets limited the gains. London Metal Exchange copper rose 0.4% on Wednesday to settle at $14,475.50 a ton.

Labor relations are tightening in Chile, the world's largest copper producer, adding to the impact of a series of mine disruptions and further tightening the supply outlook. Two unions at Antofagasta Plc's Centinela copper mine began a strike on Wednesday and said the walkout would begin affecting copper output in about two weeks. The unions said that while the mine is still supplying ore to processing plants, most mining transport and mine development work has stopped. Antofagasta has said its production forecast remains unchanged.

Meanwhile, supervisors at BHP's Escondida mine, the world's largest copper mine, are still negotiating wages under government mediation after voting to authorize a strike. A stronger dollar and broadly weaker global markets curbed copper's advance. U.S. markets pulled back from record highs, while U.S. Treasury yields remained near their highest since 2002.

Traders are also assessing whether the U.S. stockpiling demand that has driven copper's recent rally can be sustained. Washington has been slow to decide whether to impose tariffs on refined copper, taking longer than expected, while the premium of Comex copper futures over London copper has narrowed.

"Given that LME copper has recently caught up with Comex, we are now more neutral on LME copper," said Morgan Stanley analyst Amy Gower. "A slowdown in the pace of U.S. stockpiling could make the market feel more amply supplied."

LME copper rose 0.4% to $14,475.50 a ton; LME nickel rose 0.3% to $15,735 a ton; LME tin rose 0.2% to $54,279 a ton; LME lead rose 1.3% to $1,896.50 a ton; LME aluminum fell 0.5% to $3,117 a ton; LME zinc fell 0.1% to $3,763.50 a ton.

Gold Falls as Iran Tanker Attacks Briefly Lift Oil and Gas Prices

Spot gold declined as increased Iranian attacks on oil tankers briefly pushed oil and gas prices higher, while a stronger dollar also weighed on the metal. At 4:41 p.m. New York time, spot gold fell 1.3% to $4,108.97 an ounce, while spot silver fell 2.6% to $59.7605 an ounce.