More than 100 people are at risk of having contracted coronavirus after four positive tests were linked to a pub in County Durham.
Anyone who visited Stanley's Empire Club between Sunday 9 and Tuesday 11 August is asked to isolate for 14 days.
Health chiefs are working to trace everyone who was there.
The pub has closed, along with the town's Ball Alley, Phoenix Club and East Stanley Workingmen's Club, which have also been linked to virus cases.
Amanda Healy, Durham County Council's director of public health, said her concerns were "predominantly" with the Empire Club.
'Stop the spread'
"We're asking people to self-isolate because it's deemed they've been in close contact with someone who has tested positive.
"We think there's over 100 people who have been in the Empire over those three days.
"The club is working really closely with us and have gathered the addresses and telephone numbers of some of the people and we passed them on to NHS Test and Trace.
"However, it may take a little while for them to be contacted so we want to make an appeal for people to isolate to stop the spread of the virus as quickly as possible."