Some of Victoria’s recently relaxed coronavirus restrictions will be reinstated after the state recorded 25 new Covid-19 cases in a single 24-hour period.

“Today, our case numbers have hit the highest they’ve been in more than two months,” Premier Daniel Andrews said in a statement. “I know that’s not what people want to hear – but sadly, that is our reality.”

The changes come into effect at 11.59pm Sunday, and limit the number of visitors Victorians can have at home to five. Outdoors, groups of up to 10 are allowed.

“The experts tell us that, largely, the numbers are being driven by families – families having big get-togethers and not following the advice around distancing and hygiene,” Andrews said. “In fact, around half of our cases since the end of April have come from transmission inside someone’s home.”

Restaurants, pubs, auction halls, community halls, libraries, museums and places of worship will now be limited to a 20-person capacity until July 12. Gyms, cinemas, theatres and TABs – all due to reopen on June 22 with a 50-person capacity – can still open, but will now be limited to 20.

“As we’ve seen across the world, this virus has the ability to turn a few cases into hundreds in a matter of days,” Andrews said.

Relaxed restrictions around community sport will go ahead as planned, as will the opening of ski slopes and accommodation, but with “increased screening and safeguards in place”.

“I know this is not where we wanted to be. And that Victorians will feel disappointed and frustrated. I’m frustrated too. But we have to channel that frustration into action.

“We can’t let this thing get away from us. We must act – while we can.”

Professor Brett Sutton, Victoria’s chief health officer, said that he does not think the increase in cases is related to recent Black Lives Matter protests in Melbourne.

“Clearly we have had some individuals who have attended,” Prof Sutton said. “But most of the detail we’re getting in the last few days of cases are these large family outbreaks without any connection to Black Lives Matter.”

Andrews urged Victorians to only see those they need to see. “Each of us need to be aware that the more people you see and the more often you see them – the more danger you are putting people in.”

He also reiterated the importance of maintaining social distancing: “Don’t visit friends and family. Don’t go on holiday. Don’t go to work. Stay home.”

The advice to work from home wherever possible remains in place until at least until July 31.

Andrews also suggested that if high case numbers continue, the government may consider “putting whole suburbs back into lockdown”.

“This is a wake-up call. We cannot be complacent,” he said. “And the only thing between us and a second wave is what we do next.”

Read the full statement here.