As passengers took off their shoes and waited to go through security at the Jacksonville International Airport, a man in a coat, boots and sunglasses tried to bypass the checkpoint, then told an agent he had a bomb in his backpack, authorities and a witness said.

In the end, it was a hoax Tuesday night, authorities said. All Zeljko Causevic had in his camouflage backpack was a small luggage scale, a couple of batteries, a microchip and a cellphone. But the scare was enough to evacuate the airport and strand travelers on planes on the tarmac for hours.

Catherine Swan-Clark, who is seven months pregnant, was waiting to get a pat-down when she saw security agents gather around a man she believed to be Causevic, a U.S. citizen who is originally from Bosnia.

“So you’re telling me you have a bomb?” Swan-Clark heard a Transportation Security Agency agent ask him. “And he responded yes, ‘I have a bomb.’ ”

Causevic, 39, was being held on $1 million bail Wednesday. He remained silent during his brief hearing before Duval County Court Judge Russell Healey on charges of making a false report about planting a bomb and possessing a hoax bomb.

According to a Jacksonville Sheriff’s Office arrest report, Causevic approached a TSA agent Tuesday night, saying he had a device in his backpack that was “supposed to be a bomb, but it’s not.”

He also told authorities he had a “detonator,” which was a remote control device.

It was unclear whether Causevic was getting onto a flight, and authorities have not released a motive. The Joint Terrorism Task Force interviewed Causevic and the FBI, airport police and the Jacksonville sheriff’s office are continuing to investigate. Airport spokesman Michael Stewart said a package that was originally described by authorities as containing a destructive device turned out to be harmless.

Swan-Clark, of Atlanta, said she was waiting for a woman TSA agent to let her through a gate for a pat-down screening when the suspect came up next to her. He tried to make his way through but the TSA agent stopped him.

“Excuse me sir, you have to go back,” Swan-Clark, 34, said the agent told him.

Swan-Clark, who was traveling for business, said she didn’t initially think anything of it. She travels frequently and often sees people who forget to take their off their coats or shoes.

“He was calm the whole time,” she said.

The man left and then tried to enter through another security lane where an older body scanner was located. But he was again stopped.

As Swan-Clark was being screened, she saw more TSA agents gather around him and then heard him say he had a bomb.

At that point, a call went out to stop all screening and for passengers to evacuate. Swan-Clark was stuck in the screening area and unable to leave. She watched agents handcuff the suspect before being given her bags and being allowed to leave.

“I just wanted to move away from that area,” she said. “It was very scary.”

Meanwhile, passengers on arriving flights found themselves stuck on the tarmac.

Arlie Gentry was on a Southwest flight arriving from New York via Baltimore just before 6:30 p.m. Tuesday.

“We moved from one spot on the runway to another spot,” said Gentry, who was reached on his cellphone while still on the plane. “They told us we couldn’t get off the plane.”

Abut 9:30 p.m., a bus arrived to take the passengers on Gentry’s flight to a nearby hotel. Other travelers on planes were also bused to hotels.

The airport reopened about 11 p.m.

Eldina Kadiric, 22, said she and her parents have lived across the street from the Causevics for about 10 years. She said she was shocked to find out her longtime neighbor had been arrested.

“I woke up this morning and I said, ‘Wait, I know him,’ ” she said Wednesday. “It just seems like they’re normal. They’re just very normal.”