The U.S. military said it struck Iran for the second straight day, an escalation of violence that threatens to strain an already fragile ceasefire.

¡°At the direction of the commander in chief, U.S. Central Command forces have started conducting additional strikes against Iran to further degrade their ability to threaten freedom of navigation in the Strait of Hormuz,¡± Centcom said in a social media post, citing attacks on vessels in the waterway. ¡°The United States is holding Iran accountable for recent unjustified aggression against commercial shipping and civilian crews freely navigating a vital international waterway.¡±

The attacks came just hours after President Donald Trump at the NATO summit in Turkey said the U.S. would probably target Iran again. The U.S. launched attacks on Tuesday and revoked a waiver that allowed Tehran to sell oil globally, a response to attacks on ships in the Strait of Hormuz that the administration blamed on the Islamic Republic.