Traders are also monitoring reports of multiple unsold crude oil cargoes around the Atlantic Basin, with producers including Russian Federation and Nigeria cutting prices for certain grades.
West Texas Intermediate crude for September delivery slid 43 cents to settle at $67.20 a barrel on the New York Mercantile Exchange. US light crude CLc1 fell $1.15 a barrel to a low of $65.89.
Fears that the escalating tensions could lead to a slowdown in global economic growth and a corresponding hit to demand for oil have weighed on crude prices in recent weeks.
Brent crude, the global benchmark, was down 1.1% at $71.66 a barrel on London's Intercontinental Exchange.
To replace USA oil, China has been turning to the Middle East, West Africa and Latin America, according to shipping data and traders.
"The key risk to oil is the contagion risk to other emerging markets, especially those representing a major share of demand growth", said Ole Sloth Hansen, head of commodity strategy at Saxo Bank A/S. Traders "are most certainly looking for Turkey to contain the situation and come up with viable solutions". By November, those sanctions reach into the Iranian energy sector and could isolate as much as 1 million barrels of oil per day at a time when the market has little room for artificial shocks.
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Lombok's airport was now open around the clock and had significantly increased its flight schedule. A dramatic video showed one man being pulled out alive Monday by soldiers.
That is compounding worries that a deepening trade war between the United States, China and the European Union will squeeze business activity in the world's biggest economies.
LONDON-Oil prices fell Wednesday after data showed a rise in USA crude stockpiles, following days of volatile trading.
Oil prices decreased on Monday as data showed that inventories at a major US crude delivery hub rose last week. US light crude CLc1 was 35 cents lower at $67.28.
Hedge funds and other money managers cut their bullish positions on USA crude to the lowest level since June, data showed on Friday. Yet, bullish sentiment found some support from expectations that looming USA sanctions against Iran could significantly hamper its crude exports.
While uneasiness about scarce oil supplies have cooled somewhat after Opec-member Saudi Arabia and other producers pumped more, the International Energy Agency warned that renewed American sanctions on Iran and disruptions elsewhere could be challenging.
Investors are now seen weighing bullish factors that include potential supply disruptions to Iranian crude exports against more bearish indicators, such as broad greenback strength and a ramp-up in production by OPEC and its allied partners.