Oil prices rose slightly at the start of trading this week after Ukraine intensified its attacks on Russia, raising concerns about a potential disruption to Russian oil supplies.
Brent crude futures for October delivery rose 0.1%, or 8 cents, to $67.81 a barrel on Monday.
US Nymex crude futures for October delivery also rose 0.15%, or 9 cents, to $63.76 a barrel.
This comes after Russian authorities announced that Ukraine launched a drone attack on the country on Sunday, severely reducing the capacity of a reactor at one of Russia's largest nuclear plants and causing a massive fire at the Ust-Luga fuel export terminal, according to Reuters.
The acting governor of the region also reported that a fire continued at the Russian Novoshakhtinsk refinery for the fourth consecutive day on Sunday, as a result of a Ukrainian drone attack. The refinery is a vital facility, as it sells fuel primarily for export, with a capacity equivalent to about 100,000 barrels per day