MUMBAI: An outdoor campaign by Cartoon Network to promote the upcoming movie release of its late-night cult hit Aqua Teen Hunger Force triggered a police alert for a possible terrorist threat in the US city of Boston on Wednesday.

The scare spurred the Boston police to close highways, two bridges and a stretch of the Charles River before bomb squads determined the supposed bombs to be nothing more than electronic light boards (38 in all) depicting a Mooninite (one of the show's alien characters) giving drivers the middle finger.

Two men who placed the objects have been charged, state officials said. Boston authorities are reportedly seeking damages to the tune of $ 500,000 as costs incurred in responding to the scare.

Following the ruckus, Cartoon Network's parent company Turner Broadcasting released a statement: "We apologize to the citizens of Boston that part of a marketing campaign was mistaken for a public danger.

"We also directed the third-party marketing firm who posted the advertisements to take them down immediately."

The apology didn't satisfy incensed Congressman Ed Markey, who released a statement slamming the campaign: "Scaring an entire region, tying up the T and major roadways, and forcing first responders to spend 12 hours chasing down trinkets instead of terrorists is marketing run amok. It would be hard to dream up a more appalling publicity stunt. Whoever thought this up needs to find another job."

That the "suspicious devices" had been in place for two to three weeks in Boston and in nine other cities --- New York, Los Angeles, Chicago, Atlanta, Seattle, Portland (Oregon), Austin (Texas), San Francisco and Philadelphia --- is the most curious aspect of this terror-filled tale.