WOODSTOCK, Ont. - A southwestern Ontario community mounting its own search efforts alongside police for a missing eight-year-old girl is expressing frustration about the strict criteria required before police can issue an Amber Alert.

Some 40 police officers and hundreds of volunteers spent Thursday night and all day Friday combing Woodstock, Ont. for any clues to the whereabouts of Victoria "Tori" Stafford.

The Grade 3 student disappeared Wednesday after leaving school. Witnesses have since identified the petite blond child scurrying along a street with an unknown woman in video surveillance footage from a nearby high school.

It's a serious situation, but the emergency broadcast alert won't be issued, a police spokeswoman said Friday.

"It is a high alert but it's not considered an Amber Alert because it hasn't just happened," said Const. Laurie-Anne Maitland for Oxford Community Police.

"I cannot stress enough that it does not change the investigation in any way of how serious it is."

For an Amber Alert to be triggered, police must believe a child under 18 has just been abducted, is believed to be in danger of serious bodily harm and there is descriptive information of a suspect or vehicle that can be immediately broadcast, Maitland said.

Those criteria have raised the ire of some members of the community. More than 200 residents joined 40 officers from multiple police forces for an around-the-clock search.

"A lot of people are upset there was no Amber Alert put on. It should have been. It just seems very disorganized," said Woodstock resident Elaine Smith, who looked on as her neighbours handed out flyers and scoured streets, yards and fields all day Friday.

"As soon as a child's missing, that's the biggest criteria there. She could be over the border now. It can always be called off."

It wasn't long after Victoria went missing that two Facebook groups devoted to the finding the child had been created. An online petition was created on one of the pages that decried the failure to initiate the heightened signal.

Linda Patterson, president of the Block Parent Program of Canada, said while her heart goes out to the family, she believes police are acting appropriately.

"This is the system they have in place and I don't know if there could have been any changes that could have helped this time," Patterson said.

Patterson, who played a role in introducing the Amber Alert system in New Brunswick, said the reason for sticking to the rigid criteria is to ensure the public doesn't become desensitized.

"(Otherwise, people) will ignore them. They won't pay attention to them and they'll say 'Oh, well there's another one,"' she said. "(The police) are absolutely right and I applaud them for that."

Victoria was last seen leaving Oliver Stephens Public School. The video was captured by a nearby high school's camera at 3:32 p.m. Wednesday.

Police said the woman accompanying her, who they call a "person of interest," appears to be between 19 and 25 years old with long black hair. In the video she's seen wearing a white winter parka and tight blue jeans.

The blurry footage shows the pair walking briskly past several people. It doesn't appear the girl is in distress.

Police haven't yet said they suspect foul play.

The girl's parents said in television interviews Thursday night that they're offering a reward for their daughter's return.

"We just want her home, no questions asked. Ten-thousand-dollar reward," said her mother Tara McDonald.

"We just want her home safely. And we just want this to be over and done with. We don't need to know a reason -- we've racked our brains. We don't have any idea why anybody would do this."

Victoria's father, James Goris, added: "We just need the baby home, as soon as possible. And we do thank everybody for everything they've done."

Since his granddaughter's disappearance, the family has been a "wreck," Jim McDonald told Sun Media Friday.

"It's been tough. It's been very tough. To lose your grandchild, it's terrible," he said.

"I haven't been able to sleep. I haven't been able to eat. I haven't been able to do anything."

Victoria's parents declined media interviews Friday.

Provincial police and officers from Oxford Community, Waterloo Region and London are involved in the search.