SURREY, B.C. -- Metro Vancouver Transit Police are investigating an incident they're calling "extremely concerning": a woman says a stranger threatened to rape her through a message sent using Apple's AirDrop feature.

The woman spoke to CTV News about her experience, and we have agreed to conceal her identity.

She said she had gone to a friend’s house for dinner and then went to board a bus at the Newton Exchange in Surrey, B.C. at around 11 p.m. Tuesday.

“I usually take transit late all the time, and especially on that route,” she said, and added nothing like this has ever happened to her while riding transit before. “I sat down in my seat and within maybe like a minute or two, it was really quick…it just popped up on my screen.”

"I'm going to rape you," the message said in white lettering on a black background from a sender called "Justins iPhone.”

“I thought maybe like it’s a sick joke, and I wasn’t sure,” she said. “And then I was thinking well, I’ve got to take it seriously anyway. It doesn’t matter if it is a joke, because I don’t know.”

She declined the photo transfer and took a screen grab of the message. She says it was sent to her twice more.

"I think they were looking for anybody who had their AirDrop available to receive items," she said. "There were many other women on there, too. So I’m wondering whether anybody else also received those messages."

Fearing for her safety, she contacted a friend and texted a transit police number set up to allow for discreet reporting.

Eventually all the passengers got off the bus, and the woman met a friend and a transit police officer at a bus stop.

The woman later posted about her experience on Facebook to make others aware.

"I tell the transit police that I'm too scared to stand up to look around and see who it might be. I'll admit that I should have done this. I should have stood up and asked 'Justin' to show his face," she wrote online.

"Not many people are able to do what they hoped they would when they're placed in an uncertain or vulnerable situation, but I wish I had the courage to do that."

She says there were several people on the bus, including some in the front of the bus and a group of younger men near the back. Transit police confirm about 15 people were on board at the time.

Transit police said they are investigating the message, "which contained extremely concerning sexual threats."

"It’s extremely concerning. It’s absolutely disturbing," Const. Mike Yake with Metro Vancouver Transit Police told CTV News. "We take situations like this extremely seriously."

He calls the use of AirDrop to make the threats unusual, but says officers are now looking into the digital footprint the message would have left behind.

"Our investigators do have certain investigational avenues that they can follow up on," Yake added.

Police have already collected CCTV video from the bus.

In her online post, the woman wrote she was left both fearful and angry.

"When I got off that bus, I wanted to cry. Not because I was scared or upset, but because I was mad. I'm still mad. I'm mad that someone used an image to trigger fear in me. I'm mad that it worked," she wrote.

She told CTV some people who have responded to her post have tried to give advice, including carrying a weapon.

"I’m just like, I shouldn’t have to do those things because this situation shouldn’t have to come into play," she said. "These things shouldn’t be happening."

There have been reports from around the world of AirDrop being used to send inappropriate, threatening and lewd messages to strangers.

Yake says it isn’t the first time the use of AirDrop has been investigated by officers in Metro Vancouver, but adds it isn’t a tactic that’s been commonly seen on the transit system here.

The AirDrop receiving option on Apple devices can be disabled altogether, or the settings can be changed from allowing messages from everyone to contacts only.

The victim in the case is urging others to contact transit police, as she did, if they end up in a similar situation.

"Never assume it's a joke. Take appropriate steps by reaching out to a friend or family member to pick you up. Make sure you contact the transit police, or notify the police or a safety officer nearby. It's better to be safe than sorry," she wrote.

Transit police say anyone who comes across a situation on transit that makes them feel uncomfortable should text their SMS help line at 87-77-77.

Yake says investigators would like to speak with anyone that was on the same bus as the victim, or anyone that may have received any similar messages themselves on the Metro Vancouver transit system.