Sounds resembling gunsots touched off a panic Sunday in Union Station in Washington. (cineman69/Getty Images)

Loud noises that sounded like gunshots inside Union Station on Sunday afternoon sent panicked crowds running through the monumental structure, shouting and diving for cover, according to officials and witnesses.

It appeared “that the loud bangs” that sent people fleeing from the train station at the edge of Capitol Hill “were fireworks,” Kevin Donahue, D.C.’s deputy mayor for public safety and justice, said in a tweet. He also said that there was no active shooter, and that nobody was wounded.

However, in the first seconds after the noise resounded, people were uncertain about what was happening, and appeared, as described by witnesses, fearful that one or more gunmen had opened fire.

“People, they were scared,” said Lawrence Sambawei, an assistant manager of an Au Bon Pain restaurant in the station. “Some were crying, some were diving to the floor.”

The gunshot-like sounds occurred around 4 p.m., he said, about the same time as passengers who had just arrived by train were filling the station.

“Everyone was running,” Sambawei said. Their “first instinct was to run for safety.”

Sounds apparently made by firecrackers sent people fleeing in Union Station late Sunday afternoon. (Photo by Pam Arms)

Another witness, Cecilia Favela, came upon the scene after emerging from the Metro. “Everybody started screaming, ‘Gunshots, gunshots!’ ” she said.

“It was a very loud sound,” she said, and with many mass shooting incidents reported recently around the country, “we thought it was a real one.”