Several moviegoers in three different Greater Toronto Area regions in Canada were evacuated and some were treated for exposure to an unknown substance sprayed by masked men in theatres playing Hindi movies earlier this week, according to police and media reports.

One such incident happened around 9:20 p.m. on Tuesday at a cinema complex in Vaughan, York Regional Police said in a statement on Wednesday.

Numerous movie-goers started coughing after two men in masks and hoods sprayed an "unknown, aerosol-based, irritating substance into the air" in a theatre, the police said.

Around 200 people were inside when a Hindi film was playing at the time, according to police.

Several people were treated for exposure to the substance and the theatre had to be evacuated, the police said.

No serious injuries were reported.

The suspects however fled before the police arrived, investigators said.

Police said the first suspect was a Black man with a light skin tone while the second man was described as brown with a light skin tone.

York police said they were liaising with both Peel and Toronto police about similar incidents that happened this week, CBC News reported.

"Coincidentally, they took place all within less than three hours on the same evening," a York police officer said on Wednesday.

"So we are certainly looking into the possibility that these incidents are linked." Peel police confirmed in a statement that officers were called to a theatre in Brampton on Tuesday following reports of some sort of substance sprayed on the premises.

Officers evacuated the building and there were no reports of any serious injuries, it said.

No arrests have been made yet, the police said.

"It is unknown at this time if any other incidents are connected but our investigators are aware of those incidents that took place in York Region and Toronto," the statement said.

Toronto police said officers similarly got a call on Tuesday night about someone setting off a "stink bomb" in a theatre at Scarborough Town Centre.

The theatre was evacuated and no injuries were reported, police said.

When asked if the incidents were being investigated as hate-motivated crimes, Sgt. Clint Whitney said the investigation was in its early stages.

“There is no obvious indication that this is a hate-motivated crime, but we have notified our Hate Crime Prevention Unit as a precaution and they will be involved in the investigation,” he said.

In a statement, Cineplex said it was working "closely with local authorities" investigating the incident.

"Our primary focus and commitment is the safety and well-being of our guests and our team," Michelle Saba, a spokesperson for Cineplex, said.

"We thank our teams for helping guests evacuate safely," CTV News Toronto quoted Saba as saying.

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