The quake hit Iran much harder than Iraq. In Iran, authorities said at least 407 people were killed and 6,700 were injured, The Associated Press reported. The area that appeared to be the most devastated was Iran's western Kermanshah province, which is a rural area where people mostly rely on farming, the AP said.
In Iraq, at least seven people died and 535 were injured, the AP said.
Amina Mohammed said she and her sons fled their home in Darbandikhan, Iraq, as the house fell apart, the AP reported.
"I screamed to God and it must have been him who stopped the stairs from entirely collapsing on us," she said, according to the AP.
The magnitude-7.3 quake struck about 19 miles from the Iraqi city of Halabjah, at a depth of 14 miles, according to the U.S. Geological Survey (USGS).
There were two smaller quakes in the area after the 1:18 p.m. ET quake: a magnitude-5.3 quake at 1:29 p.m. ET, at a depth of 6 miles, and a magnitude-4.5 quake at 4:33 p.m. ET, also at a depth of 6 miles, according to the USGS.
The Derbandikhan Dam in Iraq experienced surface cracks and people near the Sirwan River, which flows between the two countries, had been warned to leave as a precaution, the dam manager told ABC News.
A U.S. Department of Defense spokesman said today all coalition personnel and equipment are accounted for.
The quake has not affected the campaign to defeat ISIS, Pentagon spokesman Col. Robert Manning told reporters today.
The Iraqi government has not requested earthquake-related assistance from the coalition but the coalition is ready to help if that request comes in, Manning said.
ABC News' Dyar Mohammed Rafiq, Elizabeth McLaughlin and The Associated Press contributed to this report.