Even by Las Vegas standards, it was a shocking billboard: A mannequin dangling on a hangman's noose below a black sign with the ominous words "Dying for Work."

Nevada Highway Patrol Trooper Jeremie Elliott says the emergency service calls started coming in as the sun came up early Wednesday, with drivers worried the stiff, black-suited dummy swaying at the end of a rope was a real person.

"It's a publicity stunt, obviously done in bad taste," said Elliott, adding that officials were focused on getting it down quickly to avoid distracting drivers during the morning commute.

The graphic display along the interstate was one of at least two unauthorized signs spotted Wednesday morning in the Las Vegas area. Another was white with black lettering that read, "Hope You're Happy Wall St.," and a similar mannequin hanging off the edge.

A woman who answered the phone at Lamar Advertising Co., which owns one of the billboards, labeled the act vandalism and said the display was being removed. She did not provide her name.

Clear Channel Outdoor, which owns another sign that was affected, said they pulled the display immediately and plan to work with law enforcement to punish whoever is responsible.

"We condemn the destructive behavior against one of our billboards because it is illegal and punishes our advertisers," Clear Channel Outdoor spokesman Jim Cullinan said in a statement. "This is not an innocent protest, but it is illegal and dangerous behavior that Clear Channel Outdoor and the industry will not accept."

Although the billboard alarmed drivers, it's unclear whether regulations in the area ban roadside signs with graphic depictions of suicide. A spokesman for the Nevada Department of Transportation said there didn't appear to be state regulations on the matter, and a spokeswoman for Clark County was also not aware of rules against the subject matter.

While nobody has publicly claimed responsibility for the signs, the Occupy Las Vegas group, which is affiliated with the larger Occupy Wall Street movement, posted photos of the displays on its website. Its caption says the Nevada governor's budget has slashed social programs and aid to suicidal adults.

Sebring Frehner, an Occupy supporter who posted the photos, told The Associated Press he didn't know who put the hangmen up, but applauded the message behind it.

"People saying it's in bad taste are living sheltered lives and don't pay attention to what affects the working class," he said.