HAYWARD -- A 10-year-old girl sleeping in her bed was injured when someone fired multiple rounds into her family's Hayward home early Thursday, but the shooting wasn't reported for five hours -- and police say they want to know why.

The shooting took place about 2 a.m. at a three-bedroom home in the 27800 block of Tampa Avenue near Weekes Community Park but was not reported until 7:35 a.m. according to Sgt. Ken Forkus.

The girl was shot once in the buttocks and taken to the hospital to be treated when police arrived. Police said she was expected to undergo surgery sometime Thursday to remove the bullet but that she remained in stable condition and was expected to live.

Investigators were interviewing the girl's parents Thursday to determine why no one called 911 until more than five hours later.

"We want to know whether they were aware their child was shot," said Sgt. Mark Ormsby. "If they were scared that's understandable, but we need to get to the bottom of this."

A motive for the shooting at the home, just south of West Tennyson Road, was not immediately known.

The girl, who was sleeping in a front bedroom of the home, lives there with her mother, father and three siblings -- an 8-month-old brother and two sisters, ages 15 and 23, police said. All six family members were home during the shooting. No one else was injured.

On Thursday morning, investigators had marked four bullet holes around a front window of the one-story home and had taped off the house and a residence directly next door. A few nearby homes displayed surveillance cameras, which crime scene technicians inspected.

In the driveway of the victim's home, a late-model Chevrolet Camaro showed signs of gunfire, with the back window shattered. Several other vehicles parked on the grass in the home's front yard did not appear to be hit by gunfire.

Ormsby said the home is in a "gang-infested" neighborhood, but it was not yet clear if the shooting was gang-related.

"The suspects are cowards who came out in the middle of the night and fired at this home," Ormsby said. He described the girl as a trouper who did not shed a tear and was in good spirits when police arrived.

Ferdinand Santos Castelo, 56, who lives five houses down and across the street, said he heard a series of pops sometime about 2 or 3 a.m. that woke him up. But when he peeked outside his front window he didn't see anything out of the ordinary, he said.

"I wasn't sure what it was and was half-asleep, so I went back to bed," said Castelo, who gets up at 5 a.m. for work each day.

Castelo said he did not know the family who lives in the home struck by gunfire but said neighbors on his street are friendly. But he said he frequently hears gunfire in the neighborhood consisting of homes located very close to one another.

"I hope they find who did this," Castelo said as he stood in his driveway on Thursday during his lunch break. "It's sad it had to involve a child."

Anyone with information on this case is asked to contact Hayward police at 510-293-7034.

Contact Natalie Neysa Alund at 510-293-2469. Follow her at Twitter.com/nataliealund.