(Reuters) - Multiple reports of gunfire sent a crowded mall in Raleigh, North Carolina, into chaos on Saturday, and several people were injured trying to flee the shopping center, police said.

The Crabtree Valley Mall was placed on lockdown in the early afternoon after several shoppers reported hearing gunfire and took shelter inside shops as police descended on the mall.

Raleigh Police Department dispatchers initially said shots were fired inside the mall but added that it was unclear what motivated the shooting, where exactly it happened, or whether more than one shooter was involved.

By the evening, no suspect had been arrested or identified, Police Chief Cassandra Deck-Brown told a news conference.

Deck-Brown said the investigation was continuing but left open the possibility that no actual shots were fired at all. No bullet casings were recovered and the only injuries were sustained during the chaotic rush to flee the mall, she said. Eight people were treated for minor injuries.

“We have not actually determined that there was a shooter at this point,” Deck-Brown said.

Video footage posted on social media showed dozens of shoppers rushing toward an exit. Photos showed officers searching the mall with weapons drawn.

Crabtree Valley, with nearly 200 stores, is one of the largest enclosed malls in the U.S. Southeast, according to its website. The mall did not immediately respond to a request for comment.

Tony Rice, a contributor to WRAL.com, a local television station’s website, said he sheltered in place when people began screaming and running from the mall. Rice reported that Raleigh police officers were evacuating stores in the food court area.

“I thought it was an earthquake when people started running,” Rice told WRAL-TV. “It was panic.”