Patrons dine at an outdoor restaurant along 5th Avenue in The Gaslamp Quarter in downtown San Diego, California on July 17. Photo: AFP

A restaurant in northern California is in hot water following reports that its staff failed to wear masks and patrons were discouraged from using face coverings to protect against the coronavirus.

Apple Bistro, located in Placerville, about 65 kilometers northeast of Sacramento, received a warning from local officials on Monday after numerous complaints from customers, some of whom said they were turned away for wearing a mask.

One of the signs outside the restaurant bluntly tells patrons its position on health guidelines to protect against COVID-19.

"No social conditioning. No oxygen deprivation mask. No latex dirty germ spreader," the sign says, adding "Not required here. This may not be for you."

Carla Hass, the communications director for Eldorado County, where the restaurant is located, told AFP that health inspectors decided to pay the restaurant a visit after receiving more that 50 complaints in recent days.

"Our environmental management staff met with the partner and owner yesterday to discuss with them how they could come into compliance for requiring their employees to wear face covering," Hass said.

She said if the restaurant fails to comply, health officials would suspend their permit.

A man who answered the phone at the restaurant on Tuesday said "we are not taking media calls at this time."

According to local media, the owner disagrees with the health guidelines put in place as coronavirus cases continue to rise in California. 

Customers meanwhile have taken to Yelp and Twitter to criticize the establishment and to call for a boycott.

"He asked me if I had seen the sign," one customer told the local television station. 

"I was definitely not welcomed to stay with my mask on."

Another woman said she was asked to leave when picking up an order while wearing a mask.

Other customers, however, said they didn't mind the restaurant's position on health rules.

"I have no problem," one woman told KABC-TV. 

"I'm glad to see them still doing business and they are social distancing."

California Governor Gavin Newsom recently ordered people to wear masks when in public settings as the number of COVID-19 cases rose sharply in the state.