BOSTON – Nine blinking electronic devices planted at bridges and other spots in Boston threw a scare into the city yesterday in what turned out to be a marketing campaign for a late-night cable cartoon. At least one of the devices depicts a character giving the finger.

Highways, bridges and a section of the Charles River were shut down and bomb squads were sent in before authorities declared the devices were harmless.

“It’s a hoax – and it’s not funny,” said Gov. Deval Patrick.

Turner Broadcasting, parent company of Cartoon Network, said the devices were part of a promotion for the TV show “Aqua Teen Hunger Force.”

“The packages in question are magnetic lights that pose no danger,” Turner said in a statement. It said the devices have been in place for two to three weeks in 10 cities: Boston, New York, Los Angeles, Chicago, Atlanta, Seattle, Portland, Ore., Austin, Texas, San Francisco and Philadelphia.

“We regret that they were mistakenly thought to pose any danger,” the company said.

Police said only that they were investigating where the device came from. The Department of Homeland Security said there are no credible reports of other devices being found elsewhere in the country.