Two women from southern Ontario have been arrested and charged with fabricating a story about a person they alleged was going to carry out a terror attack on a Canadian flight, police say.

Security teams based in Toronto and Edmonton launched an investigation in January after receiving an anonymous national security tip that a person from Alberta was going to launch the attack.

“A comprehensive investigation determined that this was actually a hoax,” RCMP spokesperson Sgt. Richard Rollings said.

Two women were arrested Tuesday in London in connection with the case, Rollings said. The women know each other, but Rollings would not give any information about the person in Alberta or the connection between the three.

“That will all come out in court,” he said.

No flights were grounded or delayed because of the hoax, but “substantial police resources” were tied up in the case, Rollings said.

“It did involve two national security teams, as well as officers from Brantford and London police,” he said. “Luckily, this doesn’t happen that frequently.”

“The RCMP would like to remind the public that it takes all threats to Canada’s national security seriously and to determine their credibility, we must fully investigate each and every one of them,” said Insp. Lise Crouch, the officer in charge of the Toronto unit in the investigation.

“Investigating potential threats consumes significant resources and time for the police, domestic and international, and all other agencies and partners that play a role in public safety.”

Crouch said these types of hoaxes are far from harmless pranks.

“They cause real public apprehension, result in unnecessary and very costly responses by law enforcement and divert valuable resources, which would be better allocated to serious matters that impact public safety.”

A Brantford, Ont., woman and a London, Ont., woman are both facing Criminal Code charges of comitting a terrorist hoax, causing a public nuisance and counselling an offence.

The two are expected to appear in a London court in March.