WARREN, Mass. (AP) -Searchers discovered four vertebrae and a rib bone in the Palmer woods Saturday, as they looked for clues to the disappearance of teenage lifeguard Molly Bish, investigators said.

District Attorney John J. Conte said at a news conference Saturday that other bones were also found Friday night, bringing the total of bones found to 22.

He said that all of bones were human. They were all found within 250 feet of each other and likely came from one person between the ages of 14 and 20, he said.

“We feel we’re right on track,” he said.

Conte also said he expected to know a week from Monday whether the arm bone being tested at a Virginia laboratory belonged to Molly Bish, who disappeared nearly three years ago.

Investigators believe the bones, which were partially covered in leaves and debris but not buried, may have been dragged by animals from some “point of origin” to where they were found. Police were searching animal dens in the area for more evidence.

Fifty-seven searchers braved pouring rain Saturday to comb through a rugged area of the woods filled with rocks and ledges.

“It’s very, very difficult. It’s very slick because of the rocks,” Conte said. “It’s a tribute to the search people that they’re out there on a day like this.”

The search was expected to continue until about 4 p.m. Saturday and resume Monday.

State Police Col. Thomas Foley said that police would keep searching even if DNA results proved that the bones belonged to the teenager.

“We’ll come out when we feel like we’ve covered everything,” Foley said.

A total of 28 acres in the area have been searched.

All the bones were found near where a hunter discovered a bathing suit similar to the one Bish, 16, was wearing when she disappeared from her lifeguard post at Comins Pond in Warren.

The investigation was revived when a hunter led police to the swimsuit last month. The suit was tested for DNA, but Conte said Friday that material recovered from the suit could not be used for successful DNA matching.

Other items found in the search area over the past several days – shoes, shorts, a hairbrush and a blanket – were definitely not Molly’s, prosecutors have said.

State Police Lt. Thomas Curran said members of the search team had been carrying photos of Molly given to them by her father.

“It’s just another bit of motivation to help the Bish family,” Curran said.

Molly Bish vanished June 27, 2000, as she was preparing for her morning lifeguard duty. When swimmers arrived at the beach, only her lunch, water bottle, radio and sandals were there. Her first-aid kit was open.

Conte has said the discovery of the bones has prompted investigators to look again at some suspects interviewed after Bish’s disappearance.

AP-ES-06-07-03 1450EDT