SOUTH BERWICK, Maine — State Police have more than 100 tips and a dozen investigators poring over evidence. But the blanket-covered body of a young boy, discovered Saturday in a remote, wooded section of this small town, remained unidentified yesterday.

The death of the boy, estimated to be 4 to 6 years old, is shocking enough for this community on the New Hampshire border. But the deepening mystery about the boy’s identity has baffled and saddened residents who cannot understand why no one has reported him missing and how someone could have abandoned his 45-pound body off a cratered dirt road.

“It’s enough to make you sick,’’ said Sid Hall, who lives near where the body was discovered. “I can’t imagine in my mind why someone would do something like that, but there are some sick puppies around.’’

Yesterday, authorities called the discovery a suspicious death, instead of a homicide. They would not divulge the results of an autopsy con ducted Sunday on the boy, who was 3 feet 8 inches tall with blue eyes and dark blond hair.

State Police appealed again for information concerning the boy, a Toyota Tacoma pickup truck seen on the dirt road Saturday morning, or new reports of missing children. “Somebody out there knows who this boy is,’’ said Colonel Robert Williams, commander of the State Police.

The grim discovery rekindled memories of the 1997 killing of Jeffrey Curley, a 10-year-old boy from East Cambridge, Mass., whose body was found here in a Rubbermaid container in the Great Works River.

“It’s pretty devastating to hear of a child discarded,’’ said Katie Severson of Berwick, who wiped away tears as she placed flowers near the place where the body was found.

“It just felt right to come down and pay my respects to this boy and let him know I was thinking of him and that he has a place in my heart,’’ said Severson, as her 3-year-old daughter, Natalie, sat quietly in a car seat.

State Police Lieutenant Brian McDonough, chief of the criminal division for southern Maine, called the case “extremely unusual.’’ Schools in the area have not reported an unexplained empty seat in the classroom, a widely circulated computer-generated photo of the boy has not yielded his identity, and his parents have yet to notify the Maine police.

“This boy’s face is the best-known face in New England today,’’ said Steve McCausland, spokesman for the State Police.

Authorities are widening their search from the immediate area in ever-expanding circles, McCausland said. The National Center for Missing and Exploited Children also is providing help.