Brent crude for January was at $36.78 a barrel, down $1.16, or 3.1%, by 0229 GMT, while U.S. West Texas Intermediate fell $1.24, or 3.5%, to $34.55 a barrel. Brent fell as much as 5.8% and WTI as much as 6% in early trade, hitting their lowest levels since May.
Countries across Europe have reimposed lockdown measures aimed at slowing COVID-19 infection rates which have accelerated in the continent in the past month.
"The lockdown measures announced by UK and by Italy are just adding to the deteriorating European situation," Michael McCarthy, chief market strategist at CMC Markets in Sydney said.
"A lot of traders are now looking at the U.S. and their rising infection rates and wondering if Europe is providing the model for what will happen in the U.S. in the coming weeks."
Oil pared some losses after Japan's export orders grew for the first time in two years, China's factory activity accelerated at the fastest pace in nearly a decade in October. More manufacturing data is expected from the eurozone and the United States.
Still, concerns about weakening demand and rising supplies from OPEC and the United States caused oil prices to fall for a second straight month in October, with WTI falling 11% and Brent 8.5%.
Rising supplies from Libya and Iraq, members of the Organization of the Petroleum Exporting Countries (OPEC) offset production cuts by other members and caused the group's output to rise for a fourth month in October, a Reuters survey showed.
OPEC and their allies including Russia, a group known as OPEC+, are cutting output by about 7.7 million barrels per day in a pact aimed at supporting prices.
OPEC+ is scheduled to hold a policy meeting over Nov. 30 and Dec. 1.
In the United States, the total oil and natural gas rig count rose in October for a third straight month, according to Baker Hughes data.
A tighter race in the lead-up to the U.S. Election Day and potential electoral uncertainty raised investors' caution in global markets.
"The most immediate concern for markets is that political paralysis will delay or diminish a fiscal response to the deteriorating coronavirus situation," McCarthy said.