BAKERSFIELD, Calif. -- Two families are waiting to see if a stray dog that bit their children has any diseases.

The stray had been spotted last week, but animal control officers couldn't find it. Monday it attacked two girls when they got off the school bus.

"The dog came up, and it just started biting," 11-year-old Natalie Silva said. "We were scared."

Natalie was walking home toward Lorelei Rock Drive off Kern Canyon Road. She said the dog didn't seem aggressive at first but then suddenly attacked. She was bitten on the back of the leg.

Nine-year-old Andrea Castillo was also bitten.

"First he grabbed her leg, and then he got my leg after that," she said.

Andrea's family took her to the hospital emergency room, and her injury was bandaged up.

Andrea thinks somebody dumped the dog in the neighborhood last week. Natalie's mother agrees.

"There's a couch at the end," Margarita Silva said, pointing to a cul-de-sac. "We're thinking when they dropped off the couch, they dropped off the dog."

Silva said she called animal control last week when the same dog nipped at her other daughter. Officers came out, but couldn't find the dog. This time, firefighters happened to be on the block working on a hydrant when the kids were attacked.

The mother says fire crews saw her daughter crying, helped take care of her, and then found the stray dog. Animal Control officers picked up the dog that appears to be a mix of shar-pei and Queensland.

The dog is now in held at the Kern County Animal Shelter.

"Right now, the dog's in quarantine," animal control chief Guy Shaw said. "It's going to be here 10 days, and we'll see if it gets ill."

The dog is medium sized, and didn't seem aggressive in the pen.

"But, we're not in there with it," Shaw commented.

Animal control officers estimated the female dog is about 1 year old. Shaw said it looked scared.

Andrea Castillo's mother said she didn't really want the dog put down, because she likes animals, but she's afraid it could hurt somebody else.

Natalie's mother is more blunt.

"I'd like it put to sleep," Margarita Silva said. "I feel sorry for the dog, but it's not the first time it bit them."

Shaw said the neighbors did the right thing in calling his office about the stray, even though they couldn't find it the first time when they called last week. He also said it's important for children to stay away from any stray animal.

In this case, it appears the dog went after the kids. And Margarita Silva wishes more could have been done before the dog bit the two girls.

"I'm thinking maybe they could have just come back and checked maybe to see if they would have seen the dog," she said. "I'm sure they did what they could."