Oil prices tumbled Wednesday, aggravating what’s been the worst start to any month since 2015 for U.S.-priced crude, as the White House’s tussles with major trade partners are seen as a risk to global energy demand. Prices also fell after U.S. inventory data showed an unexpected increase in supplies for last week, halting a run of what had been seven straight weeks of declines. West Texas Intermediate crude is now off more than 22% from its 2019 settlement high of $66.30 hit on April 23, which by most measures, is a return to bear-market territory. Brent has fallen 24% since the late-April high-water mark, according to Dow Jones Market Data.

The contract for September delivery shed $2.54, or 4.7%, to settle at $51.09 a barrel on the New York Mercantile Exchange, nearing a test of the sub-$50 level briefly seen in early January. Wednesday’s close is the lowest settlement for the contract since Jan. 14, 2019, according to Dow Jones Market Data. October Brent crude dropped $2.71, or 4.6%, at $56.23 a barrel on ICE Europe, the lowest finish since Jan. 3, and eroding the year-to-date gain to 4.5%, according to Dow Jones Market Data.

President said last week he will slap a 10% tariff on a further $300 billion in Chinese imports from Sept. 1, a move which sent global equity markets into a tailspin before some respite midweek. Stocks fell sharply early Wednesday in a volatile session, before staging a late day recovery.

Oil prices deepened losses when data showed that U.S. crude oil inventories increased by 2.4 million barrels from the previous week for the week ended Aug. 2, according to the EIA.  The result was not the expected eighth straight weekly drawdown that analysts had projected. At 438.9 million barrels, U.S. crude oil inventories are about 2% above the five-year average for this time of year. Trade group the American Petroleum Institute had estimated late Tuesday that inventories dropped by 3.43 million barrels last week. “The oil market appears immune to both the recent string of consecutive draw downs with U.S. stockpiles and supply disruptions in the Persian Gulf, as the focus remains on the doom-and-gloom global economic environment,” said Edward Moya, senior market analyst with Oanda. The EIA data also showed that gasoline inventories increased by 4.4 million barrels, while distillate stockpiles rose by 1.5 million barrels last week. API had expected a drop for these categories as well.

Meanwhile, Saudi Arabia Energy Minister Khalid Al-Falih and U.S. Energy Secretary Rick Perry on Tuesday expressed mutual concern over threats targeting maritime traffic in the Persian Gulf, Reuters reported. Geopolitical tensions in the area remain high after Iran seized a handful of tankers in recent weeks in the Strait of Hormuz, a major choke point for oil shipments. “Selling pressure has started to build, and as a result, crude oil has entered in bear market territory,” said Naeem Aslam, chief market analyst with TF Global Markets. “Of course there is nothing else to blame except a trade war and the sluggish global growth. I think it is likely that the [WTI] crude price may continue to move lower and perhaps break below the critical level of $50 and continue its move towards the $45 mark.”

Rounding out trading, September gasoline fell 3.9% to $1.6203 a gallon, the lowest settlement since Feb. 26, while September heating oil fell 3.8% to $1.7532 a gallon,the lowest since Jan. 3. September natural gas fell 1.3% to $2.0830 per million British thermal units, the second-lowest price seen this year.