Deputy sheriffs looked Tuesday for at least two young men who were seen leaving a department store moments after a pipe bomb left on a shelf maimed a 5-year-old girl.

The bomb exploded at a K mart on Monday night as Erin Bower grabbed a package of trash bags.The girl lost four fingers and suffered an eye injury, but Methodist Hospital spokesman David Richards said her doctor is "cautiously optimistic of partial vision in that eye."

None of the 50 other people in the store was seriously hurt.

Two young men were seen leaving the store immediately after the explosion and did not appear to be concerned with the bombing, said Detective Sgt. Mike Kouns.

The store received no warning before the explosion, and no motive for the bombing was known, said Sheriff Joseph G. McAtee.

"The store looks like everybody dropped whatever they were looking at," said Scott Minier, a Sheriff's Department spokesman. "There's blood on the tile. The trash bag area is a mess. There is a blood and merchandise scattered all over."

Minier said the bomb had a pressure-sensitive release.

"It sounded like a pop," said a clerk, Judy Kiefer. "The first thing I heard was a child screaming. A lot of people were saying, `Get out of here.' "

The girl's mother, Maurine Bower, 31, suffered a minor shrapnel injury to one of her legs and fainted. She was treated at the hospital.

Louis M. Profeta, a medical student at Indiana University, was shopping when the bomb exploded.

"I saw the little girl, her clothes were on fire and the mother was screaming. Both father and mother were covered in blood," Profeta said. "We rendered first aid and got the father and mother away, then got her stabilized."

The severed portion of Erin's hand was packed in ice and taken to the hospital, but officials said it could not be reattached.

"She still has her thumb and about half of the palm of her hand," said Barbara McGraw, a hospital spokeswoman.

Authorities brought in dogs to sniff out more explosives. None was found.