The dramatic escalation in tensions between Israel and Iran caused a spike in the price of crude and raised fears among oil traders about disruption to shipping in the Strait of Hormuz, one of the world’s most vital waterways.

Oil prices climbed over 4% on Tuesday as the Iran-Israel conflict raged with no end in sight, though major oil and gas infrastructure and flows have so far been spared from substantial impact. Brent crude futures settled at $76.

While there have been some attacks on energy infrastructure in both countries, the most oil-price-sensitive sites, including Hormuz and the major Kharg Island export terminal, have been spared.