The price of US crude and Brent climbed on Wednesday as tensions in the Middle East weighed on the minds of investors.
At the time of writing (13:52 CET) the price of US crude oil, also known as WTI, was up 3.56% at $77.39 per barrel, while Brent was up 3.08% to $80.48, as tensions in the Middle East prompt market volatility.
It comes as Iran's Supreme Leader Ayatollah Ali Khamenei has sworn revenge on Israel over the killing of Hamas' political chief, in a shock assassination that risks escalating the conflict.
Khamenei said Israel "prepared a harsh punishment for itself" after Ismail Haniyeh was killed in a predawn airstrike in the Iranian capital Tehran on Wednesday.
"We consider his revenge as our duty," Khamenei said in a statement on his official website, saying Haniyeh was "a dear guest in our home".
His comments came after Hamas put the blame for the attack firmly at the feet of Israel.
In a statement, the group said that Haniyeh was killed "in a Zionist airstrike on his residence in Tehran after he participated in the inauguration of Iran's new president".
"Hamas declares to the great Palestinian people and the people of the Arab and Islamic nations and all the free people of the world, brother leader Ismail Ismail Haniyeh a martyr," the statement said.
Israel had vowed to kill Haniyeh and other leaders of Hamas over the group's 7 October attack on Israel.