Oil prices surged above $90 a barrel on Monday as the escalating military confrontation between the United States and Iran heightened concerns over supplies from the Gulf, with shipping through the Strait of Hormuz remaining severely disrupted following another night of attacks.

The latest gains came as the US carried out a ninth consecutive night of strikes on Iran and Tehran responded with fresh missile attacks, fuelling fears that the conflict could spiral into a wider regional war and threaten one of the world's most critical energy corridors.

Brent crude futures climbed $2.30, or 2.61%, to $90.40 a barrel in early trading, after touching their highest level since June 11. The international benchmark has now gained nearly 16% over the past week, marking its strongest weekly performance since April.

US West Texas Intermediate (WTI) crude rose $1.99, or 2.41%, to $84.48 a barrel.

Prices had already climbed around 3% on Sunday.

The rally reflects mounting fears that supplies moving through the Strait of Hormuz could face prolonged disruption. 

Shipping activity through the strait remained subdued over the weekend as security concerns intensified. Data from LSEG showed that only four vessels transited the waterway on Sunday, down from eight the previous day, said a Reuters report.

Since Friday, only three oil products tankers and one Very Large Crude Carrier (VLCC) have entered the Strait of Hormuz to load crude, while no liquefied natural gas (LNG) carriers have been observed transiting the passage since Thursday.

Some commercial vessels have reportedly opted for alternative routes along Oman's coastline to reduce exposure to potential attacks, although those routes are not recognised by Iran. Maritime security agencies have also warned that some ships may be switching off their tracking transponders while passing through the region, making vessel movements more difficult to monitor.