REUTERS

All those who got up close to Champions League celebrations in the city of Porto should monitor for COVID-19 symptoms and avoid close contact with others over the next 14 days, Portugal's northern region health authority said on Sunday.

In the few days leading up to Saturday's final between Chelsea and Manchester City, big crowds of English fans, who were largely maskless and did not socially distance, took over Porto's riverside area to drink and chant team slogans.

Some 16,500 fans were allowed into the stadium but many others travelled to Porto to support their teams from the sidelines. On Saturday evening, ecstatic Chelsea fans erupted with joy in Porto's streets after their team clinched the title. 

There has been concern in Portugal the event could lead to an increase in infections after authorities decided to relax COVID-19 rules for the match, but also due to the highly contagious coronavirus variant spreading in parts of England after first being identified in India. 

All fans had to present a negative COVID-19 test on arrival. Portugal is on the British government's "green" list allowing tourists to visit the country without quarantining on their return. 

In a statement, the regional health authority (ARS Norte) said those who were in fan zones or around areas where celebrations took place should monitor for COVID-19 symptoms, including fever, cough and loss of taste or smell.

It also said people should try to "reduce contacts over the next 14 days" and strictly follow preventive measures, such as maintaining social distancing and wearing a mask.

The recommendations were made due to the high number of fans in Porto who did not comply with COVID-19 rules, ARS Norte said, adding it would "keep monitoring the epidemiological situation" and adjust its response accordingly.