Earlier Wednesday, the U.S. military reimposed a blockade on Iranian ports after Tehran attacked ships attempting to pass through the Strait of Hormuz, as the interim agreement to end the war further unraveled.

The U.S. first imposed sanctions in mid-April and lifted them in mid-June, the day after the U.S. signing an interim agreement setting a 60-day deadline for negotiations on issues such as Iran’s nuclear program, but as tensions in the Strait escalated, the negotiations stalled.

The U.S. Central Command said the U.S. carried out another wave of airstrikes before reimposing the blockade. Early Wednesday morning, Bahrain and Kuwait issued missile alerts in response to Iranian fire—a situation that occurs daily—further straining the ceasefire.

According to the Islamic Republic News Agency, at least four locations in the Iranian city of Bushehr on the Persian Gulf were attacked just hours after the U.S. announced the end of its airstrikes.