Peter Berdovsky, 27, of Arlington, and Sean Stevens, 28, of Charlestown, were each arrested Wednesday night on one felony charge of placing a hoax device and one charge of disorderly conduct, state Attorney General Martha Coakley said.
In a news release announcing Stevens' arrest, she said the men worked together to place the devices. At an earlier news conference she said Berdovsky had been hired to place the devices.
Highways, bridges and a section of the Charles River were shut down and bomb squads were sent in Wednesday before authorities declared the devices were harmless.
"It's a hoax — and it's not funny," said Gov. Deval Patrick, who said he'll speak to the state's attorney general "about what recourse we may have."
Turner Broadcasting, a division of Time Warner Inc. and parent of Cartoon Network, later said the devices were part of a promotion for the TV show "Aqua Teen Hunger Force," a surreal series about a talking milkshake, a box of fries and a meatball.
"The packages in question are magnetic lights that pose no danger," Turner said in a statement, issued a few hours after reports of the first devices came in.
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.
Complicating all of this, adds CBS News correspondent Bob Orr, is a separate bomb scare that happened earlier Wednesday at the Medical Center in Boston. Officials say a disgruntled employee is suspected of planting a phony pipe-bomb. It was not a real explosive.
The marketing company responsible for the campaign, Interference Inc., had no immediate comment. A woman who answered the phone at the New York-based firm's offices on Wednesday afternoon said the firm's CEO was out of town and would not be able to comment until Thursday.
There were no reports from police Wednesday of residents in the other nine cities spotting similar devices.
Authorities are investigating whether Turner and any other companies should be criminally charged, Coakley said. It wasn't immediately clear Wednesday who might have hired Berdovsky.
"We're not going to let this go without looking at the further roots of how this happened to cause the panic in this city," Coakley said at a news conference Wednesday night.
Those conducting the campaign should have known the devices could cause panic because they were placed in sensitive areas, she said. Turner did not notify officials of the publicity campaign until around 5 p.m., nearly four hours after the first calls came in about the devices, she and others said.
At least 14 of the devices were found, Coakley said.
"Hoaxes are a tremendous burden on local law enforcement and counter-terrorism resources and there's absolutely no place for them in a post-9/11 world," Knocke said.
Authorities said some of the objects looked like circuit boards or had wires hanging from them.
The first device was found at a subway and bus station underneath Interstate 93, forcing the shutdown of the station and the highway.
Later, police said four calls, all around 1 p.m., reported devices at the Boston University Bridge and the Longfellow Bridge, both of which span the Charles River, at a Boston street corner and at the Tufts-New England Medical Center.
The package near the Boston University bridge was found attached to a structure beneath the span, authorities said.
Subway service across the Longfellow Bridge between Boston and Cambridge was briefly suspended, and Storrow Drive was closed as well. A similar device was found Wednesday evening just north of Fenway Park, police spokesman Eddy Chrispin said.
Wanda Higgins, a 47-year-old Weymouth resident and a nurse at Massachusetts General Hospital, heard about the threat as she watched television news coverage while preparing to leave work at 4 p.m.
"I saw the bomb squad guys carrying a paper bag with their bare hands," Higgins said. "I knew it couldn't be too serious."
Messages seeking additional comment from the Atlanta-based Cartoon Network were left with several publicists.