VANCOUVER -- British Columbians are facing new COVID-19 restrictions designed to curb an alarming surge in cases that health officials have partly blamed on faster-spreading variants.

The new measures include a ban on indoor dining at restaurants and the closure of the popular Whistler Blackcomb ski resort, both of which are expected to remain in place for the next three weeks.

Provincial health officer Dr. Bonnie Henry announced the stricter rules on Monday after revealing B.C. set a new single-day record of 936 novel coronavirus cases over the weekend.

"This is a very challenging time," Henry said. "In the last six days, we've seen the start of exponential growth in new cases. We've seen more hospitalizations and more people requiring critical care and the strain on our acute care system is ramping up. We do not yet have enough people protected with our vaccines to keep our loved ones and our communities safe."

Henry said indoor social gatherings, travel between communities and the increasing number of cases involving COVID-19 variants of concern are driving much of the province's recent surge, and that a "circuit breaker" is necessary to help break the chains of transmission.

The new rules around restaurants will take effect at midnight on Monday and remain in place until April 19. Patio dining and takeout will still be allowed.

Health officials have also prohibited adult indoor group fitness activities "of any kind."

"Contract tracing has shown us that these settings amplify the spread and as a result, activities indoors in these locations need to be on hold for now," Henry said, adding that officials have been "agonizing" over the decision to impose new restrictions for days.

The rules around fitness classes and the closure of Whistler Blackcomb ski resort are also scheduled to stay in effect until April 19. One-on-one fitness lessons can continue in the meantime, Henry said.

Officials have also decided to make masks mandatory for students in grades 4 through 12 at schools across the province. Masks are also recommended, but not required, for children in kindergarten up to Grade 3.

Just a few weeks ago, there was hope that B.C.'s stable case numbers would allow officials to begin easing more restrictions. The province recently announced churches would be allowed a limited number of indoor services in the coming weeks, but Henry said the sudden rise in infections has forced them to reverse course once again.

"The previously announced order variance for limited indoor worship services that we have worked on very carefully with our faith leaders across the province will now also now need to be suspended. It is with a heavy heart that I have to announce this," Henry said.

Outdoor religious gatherings are still permitted, with several limits.

As B.C. works to get its case numbers under control, Henry urged employees to work from home when possible, and reminded British Columbians they should only be travelling for essential reasons.

"We know that people have taken advantage of the weather and the March break to go places with their family, and what that has meant is that we've seen a rapid rise of cases of people have returned to their home communities," Henry said. "This is important for us to pay attention to now."

Earlier this month, officials also announced that people were once again allowed to gather in groups of up to 10 people, but only outdoors. Henry said that variance is still in place, but urged British Columbians to stick to the same group of 10 people, and stay distanced from one another.

"If you're gathering outside – even if it starts to rain or snow, as it has – stay outside," she said. "Bending the rules gives this virus the edge."

That's especially true given the spread of variants like B.1.1.7 and P.1, which are believed to be much easier to transmit, particularly indoors. Henry also pointed to growing evidence that the B.1.1.7 variant associated with the U.K. can cause more severe illness in younger people, and that the P.1 variant associated with Brazil could be more resistant to vaccine.

While the new restrictions are likely unwelcome news to some, the provincial health officer urged people to think about the future when deciding how they will act over the next few weeks, as B.C. continues its accelerated immunization program.

"Remember that we can get through this," Henry said. "The miles are hardest when they're closest to the finish. But there is a finish in sight.

With files from CTV News Vancouver's Andrew Weichel