A person who was one of 1,600 people who attended a concert in Denmark has been infected by the <a href="https://www.thenationalnews.com/world/uk-news/2021/11/29/what-is-the-omicron-covid-variant-everything-you-need-to-know/" target="_blank">Omicron coronavirus variant</a>, the authorities said on Wednesday. The gathering took place in the northern city of Aalborg on Saturday. Hundreds of revellers were entertained by Danish DJ Martin Jensen. Denmark has already confirmed four cases of the new Omicron variant, all of whom had travelled from <a href="https://www.thenationalnews.com/coronavirus/2021/11/29/covid-patients-aged-2-and-under-most-likely-to-go-to-hospital-in-south-african-epicentre/" target="_blank">South Africa.</a> The Danish Patient Safety Authority said it could not verify if the infected concertgoer had been travelling. Everyone attending the event at Aalborg Congress and Culture Centre was asked to show a valid Covid-19 pass, according to Danish television station TV2/Nord. Government rules stipulate that people must prove double vaccination, recovery from Covid in the previous six months, a negative PCR test in the past 72 hours or a rapid antigen test in the past 48 hours to enter restaurants, cafes and indoor events. Nick Holm, director of the venue, said staff followed the rules during Saturday’s concert. “We follow the guidelines to the letter. In this regard, no one has come in without having a valid corona pass,” he said. “This applies to the audience and guests at other events in the house.” The centre hosted another event attended by about 400 people in an adjoining room while the concert was taking place. After the concert, guests had the opportunity to carry on the party in a foyer of the centre. The venue said everyone who attended events on Saturday, estimated to be around 1,900, had been contacted and urged to take a PCR test. Jensen took to Instagram to post a series of photos of the concert, with one showing him posing on stage in front of a packed audience. “It still feels like a dream,” he wrote. “Thank you so much for yesterday Aalborg!” He said he had never experienced anything like the concert and praised his fans for their enthusiasm, adding: “You sang along, had your hands up and gave everything you had to each track.” Last week, Denmark announced a new set of Covid restrictions including a return to mandatory masks on public transport and in shops. On Sunday, Danish Health Minister Magnus Heunicke denied that further curbs were needed to stem the spread of Omicron. “We have openly said that we are following this very closely and we will do what is needed when it is needed,” he said. “Nobody has an interest in Denmark being locked down again. The entire strategy is for us to have an open society with infections under control.” However, he refused to rule out travel restrictions as the Omicron variant continued to spread across Europe. In July, Denmark <a href="https://www.thenationalnews.com/world/uk-news/2021/09/10/denmark-marks-freedom-day-with-concert-for-50000-as-last-covid-19-restriction-dropped/" target="_blank">marked "freedom day" with a concert for 50,000 people</a> to celebrate the lifting of the final coronavirus restrictions. Meanwhile, the Dutch health authorities have said the Omicron variant was already in the country when South Africa alerted the World Health Organisation about it last week. The authority’s announcement on Tuesday added to fear and confusion over the new version of the coronavirus in a world hoping the worst of the pandemic was behind it. The RIVM health institute said it found Omicron in samples dating from November 19 and 23. Fourteen passengers who flew into the country on two KLM flights from South Africa last week were found to have been infected with Omicron. One women who tested positive was <a href="https://www.thenationalnews.com/world/europe/2021/11/30/couple-arrested-for-fleeing-dutch-quarantine-were-told-to-leave-despite-positive-test/" target="_blank">arrested along with her husband after fleeing a quarantine hotel</a> days later.