Due to the strengthening of the US dollar and the political uncertainty triggered by the attack on US presidential candidate Donald Trump, coupled with investors focusing on the progress of the Gaza ceasefire negotiations, oil prices fell for the second consecutive day on Monday.
Brent crude futures fell 55 cents, or 0.7%, to $84.48 a barrel (GMT 0109), having fallen 37 cents at the close on Friday.
US West Texas Intermediate crude was $81.65 a barrel, down 56 cents, or 0.7%.
The US dollar strengthened on Monday, while US bond futures slipped as investors bet that the attack on Trump increased his chances of winning the upcoming presidential election.
IG market analyst Tony Sycamore stated, "The attempted assassination of former President Trump is expected to benefit the dollar because it enhances his chances of being re-elected."
A stronger dollar typically depresses oil prices because buyers using other currencies need to pay more dollars to purchase crude.
Last week, Brent crude fell more than 1.7%, and WTI futures slipped 1.1%, as weak oil demand in China, the world's largest importer, offset strong summer consumption in the US.
In the first half of this year, China's crude imports fell 2.3% to 11.05 million barrels per day, due to disappointing fuel demand and independent refineries reducing production due to weak profit margins.
China is expected to release data on Monday showing that the economy likely slowed in the second quarter, as ongoing real estate slumps and job insecurity suppressed domestic demand, leading the market to expect more stimulus measures from Beijing.