Chaos in Boston due to 'Aqua Teen' adverts

A guerilla marketing exercise for Aqua Teen Hunger Force has caused multiple security alerts in Boston.

The bizarre debacle started after a third-party marketing firm working for Turner Broadcasting, the parent company of Cartoon Network, put up electronic light displays depicting a Mooninite character greeting bean-town citizens and visitors with an upturned middle digit. Somehow, the light boards were misinterpreted as suspicious devices.

The city swung into a full security alert. Local, state and federal law enforcement agencies shut bridges and sections of the Charles River -- and CNN reported early on Thursday morning that US Northern Command was monitoring the situation from its Colorado Springs headquarters.

Two men involved in planning and executing the stunt have been arrested, the Massachusetts attorney general Martha Coakley has confirmed. The charges they face include a felony - placing a hoax device that caused panic - and a separate count of disorderly conduct.

It remains a mystery as to why a full security alert was called on Wednesday over advertising devices that had been present in Boston - and other major US cities including Atlanta, Philadelphia, New York and Los Angeles - for the past two weeks, although Coakley attributed it to the devices having a "very sinister appearance" and "wires".

Turner Broadcasting spent most of Wednesday evening apologising for the chaos both in the form of a written statement and by on-air captions during Cartoon Network programming.

"We apologise to the citizens of Boston that part of a marketing campaign was mistaken for a public danger," said Turner Broadcasting CEO Phil Kent. "We appreciate the gravity of this situation and, like any responsible company would, are putting all necessary resources toward understanding the facts surrounding it as quickly as possible.

"As soon as we realised that an element of the campaign was being mistaken for something potentially dangerous, appropriate law enforcement officials were notified and through Federal law enforcement channels, we identified the specific locations of the advertisements in all 10 cities in which they are posted.

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

"We appreciate the commitment demonstrated by the Boston police department and other law enforcement agencies, as well as the Massachusetts Governor's Office, and deeply regret the hardships experienced as a result of this incident."