The multi-agency search for a 10-year-old Colorado girl continued in Denver's suburbs Thursday, nearly a week after she disappeared on what should have been a short walk to school.

At a brief news conference, Westminster police refused to suggest any connection between a body discovered late Wednesday in a grassy park seven miles from where Jessica Ridgeway disappeared Oct. 5 _ or even to say whether it was the body of a child.

The search for Jessica continues, spokesman Trevor Materasso said.

He also said authorities were processing evidence from the park and that no additional information was available. He left without answering questions.

Dozens of police officers reported to the Westminster police headquarters before dawn, including officers from Arapahoe and Boulder counties and other agencies.

Jessica's mother last saw her daughter walking to school Oct. 5. Police say the girl is believed to have been abducted and never made it to school, setting off a frantic search by hundreds of law enforcement officials and residents. Her parents were ruled out as suspects Thursday.

Thousands of people have posted photos of the fifth-grader in the neighborhood and online since she vanished on what should have been the short walk to school.

Police initially said the public didn't need to fear a kidnapper _ then said they were investigating whether the case might be related to that of another girl who was abducted for several hours Monday in Wyoming, among other tips they received.

On Wednesday afternoon, authorities changed course more definitively, saying they believe Jessica was kidnapped by an "unknown suspect."

The only real clue police have revealed is the discovery over the weekend of a backpack and water bottle that Jessica had with her when she disappeared. The items were found in the town of Superior, some six miles from her home. Police won't discuss what was found in the bag or testing results on it.

Adding to the mystery was a reported sighting more than 2,000 miles away in Maine of a car with Colorado license plates _ one of hundreds of leads being investigating from at least five states.

Westminster police repeatedly have urged the public to study the details of her face in a photo _ a small, gap-toothed grin, a slight bruise on her nose _ and a short home video, in hopes they may have seen something or come across the girl. They've thanked thousands of Coloradans and others for helping with a search they have insisted is focused on the area surrounding Jessica's home.

Materasso said Wednesday the investigation's focus is not the girl's parents, who are cooperating. Jessica's mother, Sarah Ridgeway, lives Colorado, and her father, Jeremiah Bryant, lives in Missouri.

"We're confident they are not involved in Jessica's disappearance," Materasso said.

Police say they are looking for any possible connection to an abduction and assault of an 11-year-old girl Monday in Cody, Wyo., some 500 miles north.

In that case, a man lured the girl into a sport utility vehicle, saying he needed help finding his puppy. The girl was released four hours later and was discovered by hunters. Police there are looking for a white man, between 55 and 60 years old, with short, strawberry-blond or white hair and a neatly trimmed mustache.