Police in Utah say they are no closer to success in their search for a man who kidnapped a 14-year-old girl at gunpoint from her bedroom in an affluent suburb of Salt Lake City.

The local community has been in shock since an intruder slipped through the window of Elizabeth Smart's room in the middle of the night and took her away.

This was not a purely random act - he'd have to know that she lived there

Wes Galloway victims' advocate for Salt Lake City police

He warned her nine-year-old sister he would hurt her if she raised the alarm before making away with the pyjama-clad teenager.

The Mayor of Salt Lake City, Rocky Anderson, is offering a $250,000 reward for information leading to her safe return.

Salt Lake City Police spokesman Scott Atkinson confirmed that the investigation had not moved on despite help from the public.

"We're getting lots of information still coming in, and nothing has led us a step closer to solving this crime," he said.

The police said earlier that they had no reason to believe the kidnapper knew his victim.

Police say the kidnapper had adequate time to get away

The abduction occurred as the house was up for sale and it would have been visited recently by prospective buyers.

The suspect is described as a white male of medium height.

According to Elizabeth's little sister, he was soft-spoken, wearing a tan coat and a baseball hat and carrying a small black gun.

He came in through the bedroom window at 0230 on Wednesday and let Elizabeth put on a pair of shoes before leaving with her.

So scared was the younger girl, that she waited two hours before raising the alert.

"A two-hour window gives anyone the opportunity to flee from this area," a police official said.

Statewide search

The Utah authorities have put in action a statewide alert - a so-called "Rachel Alert", named after nine-year-old Rachael Runyan, kidnapped and murdered in Sunset, Utah, in 1982.

About 700 people are involved in the search in Utah

Search parties have been scouring nearby foothills with dogs for clues while detectives are checking the home computer and speaking to her classmates to see if she may have become acquainted with a stranger online.

Police said they had received 1,200 tips from the public, and forces in two other states, Idaho and Wyoming, were also conducting a search.

Wes Galloway, a victims' advocate for Salt Lake City police, suggested that the kidnapper had planned his abduction carefully.

"This was not a purely random act," he said.

"He'd have to know that she lived there."

'Happy girl'

Relative Tom Smart said Elizabeth's father was at a loss as to why his little girl had been kidnapped.

"Right now Edward's going over in his mind saying, 'Who could this be?'", he said.

She's the sweetest girl, she loves sports, she's always happy

Chelsea Winager school-friend

"I'm sure all kinds of things are racing through his mind."

The uncle appealed to the kidnapper to "cut his losses" and return the girl.

A school-friend, Chelsea Winager, said Elizabeth, a harp-player in the Mormon Church, was a happy girl.

"She's the sweetest girl, she loves sports, she's always happy," she said.

"I just didn't think it would happen here. It happens all the time everywhere - I didn't think it would happen here."