The United States launched new airstrikes against Iran early Thursday, and Tehran responded by targeting Gulf countries in an exchange of fire that threatened an interim deal intended to help end the war in the Middle East.

Back-and-forth attacks, including a day earlier, have repeatedly threatened the ceasefire, but Thursday’s appeared bigger all around, with sirens sounding at least three times in Bahrain, home to the U.S. Navy’s 5th Fleet headquarters, and missiles targeting Kuwait and Qatar.

The strikes came hours after U.S. President Donald Trump said recent Iranian attacks on ships in the Strait of Hormuz signaled the end of a fragile ceasefire and threatened to escalate the conflict if they didn’t stop. That raised concerns that the region could tip back into a war that would engulf several countries and could halt energy shipments through the strait that are crucial for the global economy.

In Iran, the two days of American airstrikes have killed at least 14 people and wounded another 78, Iran’s Health Ministry said Thursday — most of those reportedly members of the armed forces.