TORONTO -- Police say marijuana dispensaries operating illegally in Toronto have been the target of violent, armed robberies but their business owners and employees often don't report them to authorities.

There have been 17 robberies of so-called pot shops since last June and eight of them were not reported to police, Supt. Bryce Evans told a news conference Monday.

During some of those robberies, Evans said employees and customers in the stores were stabbed, pistol-whipped, pepper-sprayed and shot at.

"I find it disturbing that the owners and operators of these storefronts refuse to co-operate, turn over evidence and instruct their employees not to speak to police after they become victimized."

Evans said those eight robberies were reported to police by customers or neighbours.

In one incident on Dec. 21, Evans said four or five masked men armed with guns stormed a downtown store named Canna Clinic, ordered the employees to the ground and stole cash and drugs before taking off.

A customer who was present during the robbery went to the store the following day and asked if they reported it to police, but the employee allegedly denied it occurred, Evans said.

The customer later complained about it on social media and police launched an investigating, he said.

"The employees were not forthcoming and refused to answer any question," Evans said, adding that investigators were denied access to the store's surveillance videos.

Canna Clinic's owners could not immediately be reached for comment.

The federal government is expected to table legislation in the spring to legalize marijuana, but Prime Minister Justin Trudeau has said that the current laws will stand until new legislation is ratified.

Last May, Toronto police began to crack down on the dozens of illegal marijuana shops that have popped up throughout the city. During that operation -- dubbed Project Claudia -- police raided 43 shops and arrested 90 business owners and employees.

Since then, police have conducted a concerted effort at the divisional level, according to Insp. Steve Watts with the drug squad. Police have executed 33 raids -- about one a week -- since June, he said.

"When there is large amounts of money and substances in one location, that is absolutely a target for certain types of suspects," Watts said, adding that one of the shops takes in $30,000 in cash daily.

Evans said they have made some arrests related to the robberies, but their investigations are being hampered by the lack of co-operation from owners, who they say aren't providing information and surveillance video.

"I realize there is no legal obligation to report a crime, but where is your moral sense of obligation?"

Jodie Emery, whose company, Cannabis Culture, has 22 stores across the country, said one of their Toronto locations was robbed recently. She said they called police to report it, and later officers raided the store.

"It's important to remember that it is the police and government policy of prohibition that creates the inflated value for cannabis, and therefore contributes to the likelihood of robberies and theft," Emery said in an email.