Oil prices tumbled by four percent on Monday amid growing concerns over the coronavirus' impact on global demand.
Brent, the London-traded global benchmark for crude, was down $2.81, or 4.9 percent, to $55.13 per barrel by 10:42 a.m. EST (15:42 GMT). Its previous sharpest decline in a day was 6.5 percent on September 17.
West Texas Intermediate, the New York-traded benchmark for US crude, fell $2.47, or 4.6 percent, to $50.91 per barrel. Its previous biggest loss was 4.9 percent on January 8.
The world's stock markets, especially the ones in Seoul and Milan also dropped earlier in the day amid fears of a coronavirus pandemic.
Following reports of a fourth fatal case in Italy's northern Lombardy region, Milan's stock market plunged by five percent.
Seoul's market dropped by 3.9 percent as South Korean authorities announced a surge in COVID-19 infections.
Brent oil prices had seen a 20 percent loss for a month until last week, when the prices rebounded as traders became optimistic that the virus, which has killed more than 2,600 and infected 80, 000 wouldn't continue spreading outside China.
At the same time, Giulio Gallera, Councilor for Welfare of Italy's Lombardy region, stated on Monday that the third person died from the virus in the region, thus bringing the total number of fatalities in the country to four.