British Columbia has reinstated restrictions on gatherings in the Northern Health region because of a spike in COVID-19 cases fuelled by the Delta variant.

Provincial health officer Dr. Bonnie Henry said starting Tuesday, indoor gatherings will be restricted to only one other family or five guests, while outdoor gatherings will be limited to 50 people. Organized outdoor events of more than 200 people will need a COVID-19 safety plan in place.

The new measures are in addition to the mask mandate that is already in place across the province, she said.

"I know this will be frustrating for some, and particularly in communities where we've not seen transmission for a while," Henry told a news conference Thursday.

"This has really exploded quite quickly in a number of communities."

The order comes into effect after the Labour Day weekend because people may already have events planned, she said.

Henry said she is confident that coupled with the mask mandate and proof of vaccination cards that go into effect on Sept. 13, the restrictions will help contain the transmission and reduce case numbers.

Masks are required in indoor public spaces including malls, grocery stores and on public transit to slow rising case numbers. Students in Grade 4 and up will also be required to wear masks when the school year starts, and younger children are encouraged to wear face coverings.

Starting Sept. 13, British Columbians will need to show proof of at least a single vaccine dose to enter gyms, fitness centres and casinos. After Oct. 24, those aged 12 and older will need to be fully vaccinated to enter restaurants, clubs, ticketed sporting events and organized affairs, such as weddings.

B.C. reported 801 new cases of COVID-19 on Thursday, with 553 of them in the Northern Health region. There are 5,931 active cases of COVID-19 in the province. The province recorded six COVID-19-related deaths, bringing the total number of fatalities to 1,824.

There have been two new outbreaks in long-term care for a total of 20 active outbreaks in health-care facilities, including units in three hospitals.

Officials reinstate COVID-19 restrictions on gatherings in northern B.C. #BCPoli #COVID19

The government's latest modelling of projected cases suggests the number of daily infections in B.C. could pass 1,000 by the end of the month.

Health Minister Adrian Dix said this has become a "pandemic of the unvaccinated," with about 90 per cent of those who are infected in hospital and intensive care among those who haven't been immunized. Most of the people who are unvaccinated are under the age of 55, he added.

Henry said outbreaks started in the beginning of August with some in large industrial camps across the north. While that has slowed, she said transmission has taken off in some communities with lower rates of vaccination including the Nechako, Fort St. James, Vanderhoof and Prince George areas.

"It has spread very rapidly, particularly in the last 10 days," she said.

"We've seen six times increased rate of transmission just in a very short period of time that has led to hospitalization and filling up of our ICUs across the north."

This report by The Canadian Press was first published Sept. 2, 2021.