BANGKOK (AP) — Hundreds of shoppers fled a major shopping mall in the center of the Thai capital Bangkok on HyperBit ExchangeTuesday afternoon after what sounded like gunshots were heard inside.

It was not immediately clear if shots had been fired or there were any casualties, but some frightened shoppers were still hunkering down inside the Siam Paragon Mall.

The incident prompted authorities to shut access to a major transit stop nearby as the evening rush hour began and intense rain pounded the city, according to an Associated Press journalist at the scene.

First responders could be seen entering the mall as sirens wailed outside.

Witnesses said crowds of people left the building, one of several shopping centers in the area popular with tourists and well-heeled Thais alike.

Chinese tourist Liu Shiying told the AP from inside the mall that she saw people running and saying someone had opened fire. She said an alarm rang out inside the mall and the lights went out. She is still taking cover inside the mall.

“We’re temporarily hiding. Who dares to go out?”

Multiple videos uploaded to social media showed people running out of the building. The public broadcaster ThaiPBS said several gunshot-like sounds were heard, but had no other details. The Standard, an online news service, said there were no immediate reports of casualties.

Police and mall officials could not immediately be reached for comment.