Brent oil surged past $100 a barrel for the first time since 2014 as Russia’s dramatic escalation of the Ukraine crisis sparked fears of a disruption to the region’s critical energy exports.

Futures in London jumped as much as 3.3% after a report that President Vladimir Putin has decided to conduct a special operation to "protect” the Donbas region before falling back below the key threshold. Putin announced this week he’d send "peacekeeping forces” into the two separatist regions recognized by Moscow, heightening fears among western governments of a full-blown invasion of Ukraine.

Russia is a key supplier of energy to global customers, with Europe relying on the nation for about a quarter of its oil supplies and a third of its gas.