New Delhi, July 9 -- The United States launched new airstrikes against Iran early Thursday, and Tehran responded by targeting Bahrain, Kuwait and Qatar in crossfire that again threatened an interim deal intended to help end the war in the Persian Gulf.

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 the fragile ceasefire. The U.S. struck a variety of military sites and port facilities early Wednesday after Iran targeted several merchant vessels off the coast of Oman, sparking Iranian fire then as well.

But Thursday's attacks appeared bigger all around, with sirens sounding at least twice in Bahrain, home to the U.S. Navy's 5th Fleet headquarters. T...