TORONTO -- A downtown Toronto bar issued a public apology Monday after displaying a sign that was denounced online as promoting sexual assault.

Photos began circulating on social media on Sunday of a sign inside the venue that included the words "no means yes" and also alluded to a sex act.

Management for the bar Locals Only then posted on Facebook that they were "deeply saddened, shocked and appalled" that an unsupervised staff member made the sign, which they described as "disgusting, derogatory and insensitive towards a serious issue."

"Most importantly, we extend our deepest apology to anyone who may have been affected or offended by this," said the statement, which was posted on several social media platforms.

"It is unfathomable and completely disheartening to think that we would ever have to be writing something like this, as we take extreme measures to ensure the safety of our patrons in our establishment at all times."

In the statement, management also said the employee responsible for the sign would be fired and remaining staff would undergo further training on appropriate workplace practices.

But many online called for the bar to be shut down and questioned the sincerity of the apology, posting photos that appeared to show that the bar had used similar signs in the past.

"Gross. So gross. Close your doors now," one person wrote on Facebook.

"Boycott! I'm more than happy to avoid this bar forever," wrote another.

The bar's management did not immediately respond to requests for comments. A spokeswoman for the city of Toronto said they had received no complaints about Locals Only.

The venue's website and its Instagram account were updated late Sunday with photos bearing the message "No means no."

Megan Boler, a professor at the University of Toronto who studies social media activism, said social media has recently proved effective at bringing about major change, pointing to campaigns in the U.S. that pressured Nordstom into dropping Ivanka Trump's clothing line and Uber's CEO into resigning from President Donald Trump's economic advisory council.

"I think it's part of a larger climate where we're seeing social media protests followed up with very effective things such as boycott," she said.

Taking action against a specific infraction such as an offensive sign may also seem more manageable than tackling the broader issue of rape culture and sexual assault in bars, she said.

However, that broader conversation must take place in order to effect lasting change, she said.

An advocacy group called the Sexual Assault Action Coalition, which also provides training to bars and restaurants on how to help prevent and deal with sexual assault and harassment, said it had been in touch with management at Locals Only.

The controversy comes roughly two months after the owner and an employee of another downtown Toronto bar were charged with forcible confinement and sexual assault, prompting calls for a boycott of that establishment. The city has since ordered the bar closed until May.

Earlier last year, a restaurant sparked public uproar after invoking Trump's rant boasting of alleged sexual assaults to promote its menu offerings.