Iran says it attacked US military bases in Bahrain, Jordan and Iraq, and the United States and Iran have gone back to trading attacks after a short pause in fighting.
The United States has struck Iran a second time, and Iranian state media reported explosions afterward.
NATO, the military alliance of the United States, Canada, and European countries, says it is ready to defend its members after reports that Iran is preparing to strike one of them.
Kuwait says it is intercepting Iranian drones and explosions have been heard in Bahrain, drawing two more Gulf states directly into a conflict that until now centred on Israel, Iran and US forces. US strikes continued for a ninth straight night and Brent crude broke $90.
Iran has extended its retaliatory strikes to Oman, widening a Gulf-wide escalation as US-Iran talks to end the war remain unresolved and the Strait of Hormuz standoff resets to square one.
Iran says it struck US military targets in the Gulf as Khamenei was finally laid to rest in Mashhad, four months after the airstrike that killed him. The burial, long delayed, now coincides with the truce's collapse.