The United States and Iran have exchanged another series of military attacks, threatening an already fragile effort to reduce the conflict. American forces struck military infrastructure and strategic locations in Iran after attacks on commercial vessels in the Strait of Hormuz. Iran responded by targeting locations connected to the United States and its regional allies, including Gulf states. The escalation has increased concerns about civilian safety, oil exports and maritime trade through one of the world's most important shipping routes. Diplomatic negotiations have continued through regional mediators, but both governments accuse the other of violating earlier commitments.