The ads, posted over four days, alarmed the public and authorities because the first posting warned "a child will die if no one comes to get it," police said Tuesday.

But police, who have intensely searched several areas and found nothing, said the ads could be cruel hoaxes. At this point, police said they aren't sure if the ads were posted by the same person -- or persons.

"If a person is actually trying to get rid of a child in this manner, there's several potential felony child abuse charges" they could face, Sgt. Billy Dehart said at a Tuesday news briefing.

Police will ask prosecutors if posting alarming -- but bogus -- information on the Internet that triggers wasteful police searches might come under false reporting laws or another violation, he said. Police have issued search warrants for Craigslist, an Internet service provider and an email service.

In first ad, reported to police 7:15 p.m. Friday by a concerned person who saw it, someone claiming to be a young mother said she had been kicked out of her home soon after the baby's birth, police said. A photo showed a newborn with its umbilical cord attached.

"I have just given birth and I don't know what to do with my baby," the ad read. "My BF will put it in the trash can in front of my apartments so someone can pick it up. I just don't know what to do!! Please help my baby."

The ad, which gave an email address but no name, was quickly removed, police said.

Officers systematically searched the area around University Drive in the Park Hill neighborhood, but found nothing, Dehart said.

Police tracked an Internet provider address to a Park Hill home and questioned the residents.

But investigators found no children and no connection to the Craiglist ads, Dehart said.

Investigators, however, did learn the residents had an unsecured wireless Internet connection, raising the possibility that an outsider could exploit the Web access to post the ad.

About 2:22 a.m. Tuesday, another Craigslist ads was posted saying an infant would be dropped off at the corner of Capulin and Saratoga drives in the Pikes Peak Park area of the city, police said. Officers quickly searched the area, but nothing was found.

Police said they want to educate people about the state's Safe Haven Law. It allows parents to leave their child at a fire station or hospital emergency room without fear of criminal prosecution.

Anyone with information about the posting is urged to contact police at 719-444-7000.