Oil markets jumped on Monday on concerns over potential renewed U.S. sanctions against Iran as well as conflict in Iraq.
An explosion at a U.S. oil rig and reduced exploration activity also supported prices there.
Brent crude futures, the international benchmark for oil prices, were at 57.85 dollars.
There were also concerns about the stability of Iraq, the second biggest oil producer within OPEC behind Saudi Arabia.
Iraqi forces on Sunday began moving towards oil fields and an important air base held by Kurdish forces near the oil-rich city of Kirkuk, Iraqi and Kurdish officials said.
An explosion overnight at an oil rig in Louisiana’s Lake Pontchartrain drew market attention, with at least six people injured.