Explosions are heard near a US base in northern Iraq as US-Iran fighting escalates

A series of explosions sounded near a military base hosting U.S. forces in northern Iraq and sirens rang out in Bahrain on Friday, hours after the American military said it finished its 13th night of strikes against Iran.

The conflict has flared again over the past week, as the U.S. has pounded Iran while Tehran has attacked ships in the Strait of Hormuz and targeted U.S. assets and allies in the region. The strait, which is a crucial passage for the world’s energy supplies, is at the center of the latest fighting since Iranian attacks can effectively shut the waterway, sending fuel prices soaring worldwide and causing widespread economic turmoil. The Iranian-allied Houthi rebels added further pressure this week by targeting two Saudi tankers in the Red Sea, making good on a threat to cut off an alternative route for the region’s oil.

Despite the unpopularity of the war in the U.S. and the widespread damage it has caused in Iran and to the global economy, the latest round of fighting has no clear off-ramp. Iran’s Health Ministry said 55 people have been killed and over 600 wounded in strikes in recent weeks, as fighting escalated.

Read more: AP