Toronto police say they have located one of the three Chinese nationals studying in Canada who was targeted in a kidnapping scam.

Juanwen Zhang, 20, was found safe on Saturday following reports that two others, Yue (Kandy) Liu, 17, and Ke (Jaden) Xu, 16, were also missing.

Police said they have information that suggests these students may have received threatening phone calls before disappearing.

"They're being told they need to go into hiding, not to use their cellphones, not to contact their families and not to use any form of social media or the internet," said Const. Craig Brister.

After that, he explained the scammer calls the victims' family members in China to tell them their relative has been kidnapped with demands for a "large ransom."

Police concerned for student's safety

Liu, one of the two students still missing, was last seen at 10:30 a.m. ET on Friday in the Yonge Street and Finch Avenue West area.

Brister said Saturday that police are concerned for Liu's safety. She was reported missing by her guardian, he said.

Liu is described as five-feet-six with a thin build, long black hair and brown eyes. When last seen, she was wearing a knee-length brown jacket, a white scarf, blue track pants and black and white shoes.

Yue (Kandy) Liu, 17, was last seen on Friday at 10:30 a.m. ET in the Yonge Street and Finch Avenue West area. (Toronto Police Service)

Xu, the other missing student, was last seen at 10:30 a.m. ET on Thursday around Eglinton Avenue East and Midland Avenue.

He is described as six-feet-one with a thin build. He has short black hair, brown eyes and was wearing a red winter jacket, grey pants and carrying a black backpack.

'Basically tricking people': expert

Similar scams targeting Chinese students have been reported elsewhere in Canada, police said, but this is the first time it has happened in Toronto.

Joseph Steinberg, a cyber security expert, said virtual kidnapping began by targeting the Spanish community.

It started, he explained, because scammers believed that many people from this group would be scared to contact police because they are in Canada illegally. But it only grew from there.

Ke (Jaden) Xu, 16, was last seen on Thursday at 10:30 a.m. ET in the Eglinton Avenue East and Midland Avenue area. (Toronto Police Service)

"At this point it has spread and it is pretty much targeting everybody," Steinberg said.

He added that it's hard for investigators to pinpoint who the scammer is because others have copied the scheme to turn a profit.

"These scams aren't like classical, real kidnappings where someone says, 'Pay a large amount of money and you have 24 hours,'" he said.

"It's basically tricking people into thinking that their loved one or their co-worker is in danger when that person is totally safe."

If either of the students is located, members of the public are urged to call police.

Anyone with information regarding these scams is asked to call police at (416) 808-5200 or (416) 808-4100, or Crime Stoppers at (416) 222-8477.