Mariam Makhniashvili has been missing since Sept. 14. (Toronto Police)

More police officers and other resources are being added to the search for Mariam Makhniashvili.

The 17-year-old was last seen by her family on Sept. 14, when she left for Forest Hill Collegiate Institute with her brother from their home near Bathurst Street and Eglinton Avenue W.

The sister and the brother separated to enter the school by different doors. Mariam has not been seen since.

Toronto police have now declared they are conducting a level 3 search — the highest level possible.

The change in classification from a level 2 search means police can now enlist canine units and draw officers from other city divisions to help in their efforts.

Staff Insp. Larry Sinclair said Friday the teen's disappearance is "completely out of character."

"She's been in Toronto for less than 90 days. To the best of our knowledge she has no friends and her only relatives in Canada — North America — are her parents and her brother. So that was the reason we stepped it up."

Sinclair also asked residents within a radius of three kilometres to check their property in case the girl is there.

"Mariam, all we're asking for is for you to contact [your] parents, the police, somebody that you know that we don't, just to let us know that you are safe," Sinclair said.

No foul play suspected

School principal Peggy Aitchison said she thinks an abduction in front of the school in the morning seems unlikely.

"This is a very busy, populated area at that time and so the thought that somebody could jump out and snatch someone and haul them away — it just doesn't make any sense," she told CBC News.

Mariam's parents, Vakhtang and Lela, reported her missing when she did not arrive home from school Monday afternoon.

She did not attend classes that day, said Aitchison.

The girl's parents said there was no dispute or argument that would have prompted her to run away.

The Makhniashvili family has been in Toronto for only a few months.

"There's nothing to lead me to believe that there's anything strained with her relationship with her parents," said Det. Steve McIlwain, the lead investigator in the case.

He added that while police say there is no evidence of foul play, police are not ruling anything out.

Vakhtang Makhniashvili said Mariam had not yet made friends since she had only been at school for a week.

The family moved to Toronto from the Republic of Georgia for a better life. Police have also contacted Mariam's family in Georgia, but that has not provided them with any information that could help in the search.

Mariam is described as five-foot-three with light-brown, shoulder-length hair and brown eyes. She was last seen wearing black pants, a light blue shirt and a dark blue jean jacket.

She was carrying a large black backpack with a green stripe.

With files from The Canadian Press