Brent touched $110 a barrel for the first time since May on Friday on worries that escalating tensions in the Middle East could further tighten supplies, while investors assessed how much diesel Russia could supply ‌to the global market, according to Reuters.

At least nine commercial ships have come under attack near Hormuz since Sunday as Iran tries to choke off crude oil exports through the strait. The “energy ceasefire” that President Donald Trump tried to broker between Ukraine and Russia has quickly unraveled.

Iran allied Houthi militants in Yemen have repeatedly fired missiles and drones at Saudi Arabia this week.

Brent crude futures settled $3.94, or 3.7%, higher at $109.86, the highest since May 19, while US West Texas ‌Intermediate crude futures closed $3.44, or 3.5%, higher at $101.41, the highest since September.