BOSTON -- An apparent marketing ploy for a social-networking Web site prompted Newton city officials to call the state's bomb squad out early Monday.

Workers arrived at the school at 360 Lowell Ave. at about 5:30 a.m. to find four small black backpacks hung on a fence near the school, Newton School Superintendent Jeffrey Young said.

Police and fire crews were alerted and they called the state bomb squad, which brought its bomb-defusing robot in to inspect the bags. They were filled with newspaper, $1 bills sticking out of each one.

Newton police said the backpacks also contained materials related to a social-networking Web site geared toward teenagers. They did not contain anything harmful, but the incident is under investigation by Newton police.

The founder of the Web site, Sofia Loginova, 18, said that she had nothing to do with the incident, the Boston Globe reported Monday afternoon.

"It's early in the investigation, and we're going to use the cooperation of the state police, the fire department and the schools and we're going to get to the bottom of this," Newton police spokesman Lt. Bruce Apotheker said.

No one was injured, and classes took place as scheduled.

Young said he did not know who was responsible for placing the backpacks at the school.

"If it was a marketing ploy it was unfortunate, immature and disrespectful of our school," Young said.

He said it was a concern that so many city resources had to be employed to deal with something that may have been a marketing stunt.

"I don't have any indication at all that any Newton student had anything to do with this," Young said.

If students were found to be involved, he said, regular disciplinary procedures would take place. The district attorney's office is involved.

In February, two men were arrested and charged after a marketing stunt for a cable cartoon show went awry, Boston authorities alerting bomb squads to collect lit-up electronic devices that had been posted around the city.

Turner Broadcasting, which airs the cartoon, settled with the city of Boston for millions of dollars in expenses incurred during the investigation.