LaFOLLETTE, Tenn. (WVLT) -- Authorities in Campbell County are still searching for the man they say robbed the People's Bank of the South of LaFollette.

"It puts everybody on alert," said LaFollette Police Chief Jimmy Jefferies.

The People's Bank in LaFollette opened Monday to a robbery at gunpoint. Police say a white man, 6 feet tall, about 40, was responsible.

"He was wearing a hoodie and baseball cap, and had his face covered with what was possibly a bandanna," said Jefferies. "Came in, with some type of semi-automatic handgun, and had demanded money."

Police tell us he had a very slender build, about 150 pounds.

The suspect ran away with the cash. Campbell County Sheriff's deputies, LaFollette police and FBI swarmed the area, and nearby businesses went on lock down.

"Knox County sent a helicopter, so we had an air unit searching, we searched the area for him, and as of right now, we're going to continue our investigation," he said.

"It was definitely a different experience," said Melinda Shiflet, "You don't expect to come to work and get a phone call saying hey you can't let anybody in or you can't go out cause we got robbed."

Shiflet says the Diner across the street wasn't open yet, but staff holed up inside.

"It was crazy. It was definitely crazy," she said.

Even Campbell County High School locked its doors.

"They said that there was a robbery at a bank, so we had to sit in class for like two hours," said CCHS senior Duran McGhee.

"The school was in lock down, It was within a mile, mile and half of the robbery, and he was armed," said Jefferies.

McGhee and student Graham Roy say most students were calm, but thought back to the school's fatal shooting in 2005.

"That's what makes everybody afraid. After that, it just changes everything," said McGhee.

Authorities gathered evidence at the bank, while other crews keep looking.

"The last sighting we had of him, we have people still down in that area searching for him," said Jefferies.

A reward is being offered for any information which leads to the arrest of this individual. Anyone with information is asked to please call the Knoxville FBI at 865-544-0751 or the LPD at 423-562-8331.