US-Iran war, Aug. 31 -- Oil prices rose by more than 1% on Monday after the US launched an attack on an Iranian island in the Strait of Hormuz, prompting retaliation from Tehran and intensifying the Middle East conflict as it entered its sixth month.

Brent crude futures gained $1.08, or 1.23%, to $89.18 per barrel. Meanwhile, US West Texas Intermediate (WTI) crude futures advanced 92 cents, or 1.10%, to $84.32 per barrel.

The US military on Sunday targeted Iranian rocket launchers that were preparing to deploy mines in the waterway, according to Captain Tim Hawkins, a spokesperson for US Central Command. The strike ended several weeks of relative calm in the region.

Iran has also started launching attacks against US forces stationed in...