OLEY, Pa. -- School bus driver, Otto Nuss, 64, is being charged with one count of federal kidnapping, and could face additional charges, according to FBI spokeswoman Linda Vizi in Philadelphia.

The missing Berks County, Pa., school bus with 13 students on it was found Thursday afternoon in Maryland, more than 140 miles away from the private school where it had been expected that morning.

Police said that when the bus stopped at a gas station near the intersection of Interstate 95 and 495 in Prince George's County, Md., students waved their arms to attract the attention of an off-duty police officer.

"The children were waving out the window. An off-duty police officer approached the bus and took him into custody," said Trooper Ray Albert, State Police.

Nuss apparently wanted the students to see Washington, DC.

"What he told the police officer, apparently was that he had these children and he intended to take them to Washington, DC, to see Washington, DC, and wanted their parents to know they were safe and fine," said Peter Gulotta, FBI Spokesman.

Police reported that Nuss had a loaded semi-automatic rifle on board. The FBI said that none of the children were threatened or harmed.

The bus had picked up the private-school children, who are ages 6-15, at Oley High School at around 8 a.m., and was to have taken them to Berks Christian Academy in Exeter, about six miles away.

Distraught parents at the Oley Township Municipal Building were elated when they were told that the bus had been found and their children were safe. They boarded a bus to go to Maryland to be with their children.

"We're sending two counselors along down. We're sending their ministers along down, plus a police escort. They will be brought back and they'll be interviewed once they get back here," said Chief George Endy, of Oley Township Police.

Nuss will have his first court appearance Friday.

Nuss started driving for Quigley Bus Service in September. That's after he lost his job at Mrs. Smith's Pies. Nuss had worked at Mrs. Smith's for 13 years. He lost his job when the company downsized last year.

The school district's superintendent said that Nuss passed both the criminal and child abuse background checks required to get his job with the bus company.

Neighbors who saw him Sunday said he acted a bit differently.

"He's normally very jovial and he was more somber. ... It's nothing you could put your finger on," neighbor Scott Postelo said.