TORONTO -- Ontario Premier Doug Ford has expanded new social gathering restrictions across the entire province, saying that "alarm bells are ringing" as COVID-19 cases continue to surge.

In a rare weekend press conference, Ford said the province needs to take "decisive action" to stop the spread of the disease.

Effective immediately, new gathering sizes will be capped at 10 people indoors and 25 people outdoors for at least the next 28 days. The previous gathering limits were 50 people indoors and 100 people outdoors.

"We need to take decisive action like we did in the early stages of COVID-19," Ford said. "Too much of it has been tied to people not following the rules - people who think it's okay to hold parties, to carry on as if things are back to normal."

"We can't have these wild parties right now. It's just way, way to risky. Don't try to get around the rules."

Ford said the decision to cap gathering sizes was made based off the advice of the Chief Medical Officer of Health Dr. David Williams.

The new gathering rules, which already went into effect for Toronto, Peel Region and Ottawa on Friday, apply to "unmonitored social gatherings and organized public events" held on private property or in parks. The restrictions do not apply to events or gatherings held in "staffed businesses" or facilities such as movie theatres, banquet halls, gyms or convention centres.

Those facilities can still have 50 people indoors as long as people maintain proper physical distance from anyone outside their 10-person social circle.

The new rules also do not apply to places of worship or wedding ceremonies, although large receptions held in private residences, backyards or parks will fall under the gathering limits.

Ford stressed that most large facilities and restaurants are implementing strict protocols to ensure a safe environment.

In addition to the new gathering restrictions, the premier said that his government will issue hefty fines of up to $10,000 for anyone who organizes a private gathering that exceeds the limits. This is in addition to the current $750 fine for those caught violating COVID-19 rules.

Ontario recorded another day of more than 400 COVID-19 cases on Saturday, with 407 new infections. Saturday's case count is also an increase from Friday when 401 new infections were reported.

The seven-day rolling average has now increased to 312, up from 287 on Friday. 

"The increasing number of COVID-19 cases is extremely concerning," Health Minister Christine Elliott said. "We cannot risk our hard-earned progress. We will never hesitate to protect the health and wellbeing of all Ontarians."

Markham Mayor Frank Scarpitti, who pressured the government this week to cap gathering sizes in York Region, thanked Ford for listening to his concerns. 

"This speaks to the seriousness of this issue," Scarpitti said. "We cannot let another weekend go by without taking swift action. Violators who behave recklessly and refuse to follow the rules or take necessary safety precautions should face steep fines as they are risking their health and the health of others."