The Islamic Revolutionary Guard Corps (IRGC) has declared the Strait of Hormuz "effectively closed" following an attack on two oil tankers and an Omani port. This means that more than 20 percent of the world's oil is exported from the Persian Gulf. Crude oil and gasoline prices are expected to increase when trading resumes on Monday. The IRGC has warned that passage through the strait is unsafe due to the ongoing conflict between the U.S. and Israeli military activity.