The Lancashire district is overtaking Leicester as a coronavirus hotspot in England, according to official data.
The professor. Dominic Harrison said he would be “reluctant” to impose a local blockade.
The number of cases in the district nearly doubled to 118 in the past week, up from 63 in the previous week.
The latest figures are subject to daily review, but reflect the position on Sunday evening.
They include stricter limits for visitors from another family and officials have urged people to hit their elbows instead of handshakes and hugs.
New cases in Leicester, where there is a local block, dropped to a rate of 77.7, with 276 new infections, compared to 429 the previous week.
By Daniel Wainwright, BBC England Data Unit
Data on new coronavirus cases are published every afternoon, which means that new results for the previous days are added at all times.
So far, looking at the week until Friday, Blackburn with Darwen has recorded double the number of cases he has had in the previous week, while the cases in Leicester – which is in a localized block – seem to be falling.
On Wednesday, both areas reported 35 new cases. However, with Leicester having a population more than double Blackburn with Darwen, this has given the Lancashire district a higher rate of new cases per 100,000 residents.
If Blackburn with Darwen takes the top position from Leicester it should become clearer over the next two days.
Most of the new cases in the Blackburn area were among the South Asian community centered on terraced houses with a high number of occupants, public health officials said.
Professor Harrison, director of public health in Blackburn with Council Darwen, has warned that cases will continue to rise.
He said, “We should be concerned that the numbers have gone up, but I expected it entirely and I expect it to go up again this week.”
The professor. Harrison warned that a local blockade could be imposed if things were not changed, but added: “We would only use those powers as a last resort.
“We had good cooperation, so I would be very reluctant to use the powers.”
Over the weekend it was revealed that the contact tracers had only reached about half of Covid-19’s contacts in Zone.
Sam Ali, of the Switch Community Community Organization in town, said: “We have all been impressed.
“Anyone across the country wouldn’t want to be on the radar to get into another block, but it’s important to realize that the pandemic is still here.
“We have to wear the appropriate masks, we have to wash our hands, we have to stay away.
“Blackburn is a fantastic city. From this we will become stronger.”
Steve Hartley, 52, who lives in Darwen, said: “You see more people in the masks, but many people are not socially spaced or worn.
“It’s shocking, but some people still aren’t taking it seriously despite everything that’s going on.
“Now many stores have window signs that tell people they can’t go in without a mask.”