DUBAI, United Arab Emirates (AP) — The United States intensified its strikes against Iran on Thursday, hitting targets farther north and firing into a ship the U.S. accused of trying to break its naval blockade on the Islamic Republic. Iran retaliated by launching missiles and drones at U.S. allies in the region, and warned its attacks may escalate.

The interim ceasefire agreed to last month has collapsed, and the region has endured days of back-and-forth attacks by the U.S. and Iran as they battle for control of the Strait of Hormuz. Iranian officials say U.S. strikes have killed more than 35 people and wounded over 300 others.

READ MORE: U.S. launches more strikes, tightens naval blockade as Iran hits Gulf allies

For the first time in this latest round of violence, strikes also reached into areas around Iran's capital, Tehran, showing a widening set of targets for the Americans. The U.S. launched a second wave of strikes late Thursday, saying it was aiming to "further degrade" Iran's military capabilities.

When the U.S. and Israel launched the war on Iran on Feb. 28, Tehran effectively closed the strait to shipping traffic, a move that sent the price of oil soaring and gave Iran major leverage in negotiations.