The United States launched new airstrikes against Iran early Thursday, and Tehran responded by targeting U.S.-allied Mideast 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.