Oil prices rose by around 3% on Thursday amid growing concerns that the Strait of Hormuz could remain closed for an extended period, while global supply remains constrained as production facilities continue to reduce output.

Brent crude futures climbed 3.7% to $84.41 per barrel, while U.S. crude futures rose 4% to $77.59 per barrel.

According to officials cited by Reuters, Iraq, the second-largest crude oil producer in the Organization of the Petroleum Exporting Countries, has reduced its production by about 1.5 million barrels per day due to limited storage capacity and the closure of a key export route.

Meanwhile, Qatar, the largest producer of liquefied natural gas in the Gulf, declared force majeure on its gas exports on Wednesday. Sources told Reuters that returning to normal production levels could take at least a month.

Shipping through the Strait of Hormuz—a critical maritime route for nearly one-fifth of the world’s energy consumption—has been almost completely halted for the fifth consecutive day, following the ongoing war with Iran and the subsequent Iranian response.

In a note to clients, JPMorgan Chase said that Iran has so far refrained from targeting most of the world’s key energy infrastructure. However, the bank warned that risks to shipping remain extremely high, noting that its estimates indicate around 329 oil tankers are currently stranded in the Gulf.