(Updates with index/price moves and geopolitical news from the first paragraph.)

US equity indexes fell as crude oil jumped after an Iran-backed militia group hit energy sites in Saudi Arabia, one of the world's largest oil exporters.

The Nasdaq Composite declined 0.2% to 26,472.3, the S&P 500 retreated 0.3% to 7,693.4, and the Dow Jones Industrial Average dropped 1% to 52,865.6 after midday Tuesday.

Energy and utilities topped gainers intraday, while healthcare, financials and consumer staples led decliners.

Yemen's Tehran-backed Houthis attacked energy facilities and cities in US ally Saudi Arabia on Tuesday, wounding more than 70 people and underscoring the risk of the Iran conflict escalating into a wider regional war, Reuters reported. Saudi Arabia said the attacks stopped operations at several energy facilities in the kingdom's south, Bloomberg reported while noting a pick-up in buying by China, the world's largest importer.

The front-month US West Texas Intermediate crude oil contract climbed 1.7% to $93.07 per barrel, and global benchmark North Sea Brent advanced 1% to $97.99 per barrel.

Gold futures fell 0.8% to $4,439.9, and silver futures declined 1.5% to $66.65.