Two earthquakes struck Iran near the Bushehr nuclear power plant Wednesday morning, during a tumultuous day in the country.

A 4.9-magnitude quake occurred around 9 a.m., local time, followed by a 4.5-magnitude aftershock 30 minutes later. Iranian state media reported there were no casualties and rescue teams were at the scene in the southern part of the country. The first earthquake hit at a depth of about 6 miles, according to the United States Geological Survey.

People who felt the earthquake around the site reported light shaking.

The nuclear plant was designed to withstand quakes up to magnitude-9. Iran is on major seismic faults and frequently experiences earthquakes. Its hard, mountainous landscape can prevent damage from mild to moderate earthquakes.

Wednesday’s quake came on the heels of Iran launching ballistic missiles at two Iraqi bases housing American military personnel. The country had earlier threatened retaliation for the U.S. killing of Quds Force leader Qasem Soleimani, a military official the Trump administration said was planning “imminent” terrorist attacks against U.S. diplomats and soldiers in the region.

Also Wednesday, more than 170 people aboard a Ukrainian passenger jet died when the plane crashed shortly after takeoff from Imam Khomeini International Airport, south of Tehran.

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