World oil prices crashed on Monday, fuelling a furious sell-off on stock markets that were already buckling from the spreading coronavirus outbreak.
Stocks tanked as the global oil market plunged 30 per cent at one stage after top exporter Saudi Arabia slashed its prices after Russia pulled out of the Opec+ alliance over production cuts.
Major US indexes plunged more than 7 per cent, with the Dow finishing more than 2,000 points lower in its worst session since 2008, after a 15-minute halt to trading early in the session triggered by a 7 per cent drop.
In Paris, the CAC-40 index lost more than 8 per cent, also its worst daily drop since the 2008 financial crisis, while the Dax blue-chip index in Frankfurt had its sharpest single fall since 2001.
Later in Brazil, the Ibovespa index finished down more than 12 per cent.
"The markets have passed from panic mode into pure hysteria," said Ayush Ansal, chief investment officer at trading company Crimson Black Capital.
"Markets were at the breaking point before Saudi Arabia's decision to launch an oil price war but this latest development has taken them beyond that."
Saudi Arabia opened the taps on Monday, slashing oil prices after Russia refused on Friday to join producers in cutting output to support prices.
The steepest oil drop since the 1991 Gulf War sent investors fleeing for safety alongside mounting fears over the worsening coronavirus, which has led Italy to lock down a large area of its north.
Later on Monday, Italian Prime Minister Giuseppe Conte announced that he was extending the lockdown to the entire country.
"This will be remembered as Black Monday," said analyst Neil Wilson at trading site Markets.com.
Italy's stock market took the heaviest battering after a large part of the country's northern region was sealed off, including Milan and Venice, as authorities struggled to contain the spread and impact of coronavirus.
At the end of an exceptionally volatile trading day, Milan's FTSE MIB index was more than 11 per cent lower.
As the disease claims more lives around the world, dealers are shedding riskier assets for safe-haven investment.
Gold and the yen are surging while US Treasury yields are at record lows. The dollar was broadly lower against the yen, euro and other currencies.
While governments and central banks have unleashed, or are preparing to unleash, stimulus measures, the spread of Covid-19 is putting a huge strain on economies and stoking concerns of a worldwide recession.
Trading floors in Asia were also a sea of red, with Tokyo plunging more than 5 per cent, Hong Kong more than 4 and Sydney more than 7 per cent.
Saudi equities also tanked, with oil titan Aramco's shares leading the plunge. The Dubai, Kuwait and Abu Dhabi exchanges also suffered sharp drops.
Oil majors bore the brunt of a fierce wave of selling while other commodities company's also posted heavy losses.
Hong Kong-listed Cnooc tumbled 17 per cent and PetroChina more than 9 per cent, while in Tokyo, Inpex dived 13 per cent.
In Sydney, Santos plummeted 27 per cent and Woodside Petroleum fell 18.4 per cent.
In the US, Exxon Mobil slumped 12.2 per cent, while mid-sized producer Occidental Petroleum plummeted 52.0 per cent and oil services titan Halliburton 37.6 per cent.
Brent Crude: DOWN 24 per cent at $34.36 per barrel
West Texas Intermediate: DOWN 25 per cent at $33.13 per barrel
New York - Dow: DOWN 7.8 per cent at 23,851.02 (close)
New York - S&P 500: DOWN 7.6 per cent at 2,746.56 (close)
New York - Nasdaq: DOWN 7.3 per cent at 7,950.68 (close)
London - FTSE 100: DOWN 7.7 per cent at 5,965.77 (close)
Frankfurt - DAX 30: DOWN 7.9 per cent at 10,625.02 (close)
Paris - CAC 40: DOWN 8.4 per cent at 4,707.91 (close)
Milan - FTSE MIB: DOWN 11.2 per cent at 18,475.91 (close)
EURO STOXX 50: DOWN 8.5 per cent at 2,959.07 (close)
Tokyo - Nikkei 225: DOWN 5.1 per cent at 19,698.76 (close)
Hong Kong - Hang Seng: DOWN 4.2 per cent at 25,040.46 (close)
Shanghai - Composite: DOWN 3.0 per cent at 2,943.29 (close)
Dollar/yen: DOWN at 102.42 yen from 105.39 yen at 2200 GMT
Euro/dollar: UP at $1.1448 from $1.1284
Pound/dollar: UP at $1.3112 from $1.3048
Euro/pound: UP at 87.28 pence from 86.48 pence