Kuwait, Bahrain, and Qatar sounded missile alert sirens early Thursday morning warning of an Iranian attack after the United States launched a new round of airstrikes targeting Iran.
There was no immediate word of damage in the three Gulf Arab countries. Kuwait's military said it was actively intercepting incoming drones and missiles.
On Wednesday, Iran launched attacks on Bahrain and Kuwait over an earlier round of U.S. airstrikes against Iran. The latest US strikes began Wednesday, hours after President Donald Trump said that recent Iranian attacks on ships in the Strait of Hormuz signalled the end of the fragile ceasefire.
The action raised fears that the war in Iran could reignite, coming just a day after the US military hit a variety of military sites and port facilities following Iran's targeting of several merchant vessels off the coast of Oman.
Military officials said in a social media post Wednesday that the latest strikes were intended to "further degrade" Iran's ability "to threaten freedom of navigation" in the strait, through which a fifth of the world's traded oil and natural gas passed before the war began with US and Israeli attacks on February 28.
Iranian state media reported explosions in several locations, including Bushehr, home to Iran's nuclear power plant complex, and the southern port cities of Chabahar, Konarak, Bandar Abbas and Sirik.
Trump warns that it will get 'much worse' if attacks on shipping happen again
