A wedding reception of more than 100 guests was interrupted by police in Blackburn.
Blackburn and Darwen took further action on July 14 after a spike in Covid-19 affairs to try to avoid a local Leicester-style lockdown.
Police said the event at the Waheed Buffet and Banquet Hall on Randal Street was a “significant violation” of restrictions putting people “at risk”.
Manchester Police also attended a marquee wedding with 50 guests.
The organizer of the wedding at Whalley Range in the town received a fixed penalty notice.
The rally in Blackburn on Sunday was dispersed and no further action was taken.
Lancashire Deputy Police Chief Terry Woods said there were between 100 and 120 people at the scene.
He said: “The vast majority of these people were invited to leave, they were very submissive, but in fact the wedding reception was closed and there were only a small number of people left.
“Today, future action will be considered with local authorities to see what we can do with these premises to prevent this from happening again.
“For businesses, we know it’s tough, but we’re going to name and shame places that flout regulations at this point and there will be consequences. “
In a statement released on Sunday, police said: “Disappointing incident in Blackburn tonight.
“Agents attended a report of a significant violation of Covid restrictions and found more than 100 guests at a wedding reception.
“This is a clear violation of local and national restrictions that puts everyone at risk.
“The officers spoke with the participants and at the instruction of the police, the rally was dispersed without further problem.
“Please work with us to keep everyone safe by following guidelines and restrictions. “
By Daniel Wainwright, BBC England Data Unit
A month later, since tighter restrictions were introduced in Blackburn with Darwen, compared to most of the rest of England, the region still has one of the highest rates of new coronavirus cases.
In the week to August 12, 141 new cases were registered, 20 more than the week before.
This equates to about 94 cases per 100,000 population in the past week.
Official data for England released on Sunday only shows Northampton, which has recorded hundreds of cases following an outbreak at a sandwich shop, and Oldham currently has higher rates of new infections than Blackburn with Darwen.
Borough Public Health Director Dominic Harrison said: “It is not fair to the majority of the population who are sticking to the advice we have given.
“A lot of people have made sacrifices and for them something like that is not right.
“As a council, with the police, we will seek to take stronger action than we have done so far on events like this over the next few weeks. ”
He said coronavirus levels in the region are currently “high but low, but not yet as fast as we expected.”
Greater Manchester and parts of Lancashire have local restrictions in place to prevent people from socializing with other households.
Police are also concerned that emergency responses are being delayed due to the number of 999 calls regarding violations of social distancing.
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