A 10-year-old boy was in critical condition Sunday after three pit bulls (search) escaped from a home and went on a rampage, attacking six people before police shot and killed dogs, authorities said.

No charges had been filed Sunday, but McHenry County (search) Sheriff Keith Nygren said it was being investigated as a crime scene.

Neighbors said the attacks started late Saturday afternoon when children going door-to-door for a fund-raiser arrived at the home of Scott Sword, 41, who owned the dogs.

"We had music playing, and I heard this bizarre sound," said Debby Rivera, who lives three houses away. "I looked out the window, and I saw a young boy. The dogs were just jumping on him."

"The screams were horrible," she said. The dogs were "relentless, like they were possessed."

The pit bulls attacked the two children, and when the dogs' owner tried to stop them, the dogs turned on him and bit off his thumb, Nygren said. The boy's father also tried to protect his son and was attacked. The dogs went after another neighbor as well.

"The scene sprawled over a couple blocks, it was a very chaotic scene," said Lt. Michael Douglas of the Cary Fire Protection District (search).

Residents threw rocks at the dogs and honked car horns to try to distract them from attacking before police arrived and shot the animals.

Jim Malone said he and a neighbor tried to beat the dogs back with baseball bats. "He'd hit them, they'd run, and they'd come back," Malone said. "This went on for 15 minutes."

The boy who was attacked, Nick Foley, was hospitalized in critical condition Sunday. His friend Jordan Lamarre, also 10, was in serious condition. Nick's father was listed in good condition. Sword and two others were treated for injuries and released.

Last week, another 10-year-old boy in Colorado was mauled by a pack of pit bulls that attacked him in his own back yard. The boy was in critical condition after the attack, and the hospital said Sunday his family had requested no further information about his condition be released.

The attack in the Denver suburb of Aurora came two days after the City Council banned pit bulls and other "fighting dogs." Owners who already had the dogs could keep them if they paid a $200 annual license fee.