Host cities of Euro 2020 football matches need to better monitor the movement of spectators, including before they arrive and after they leave the stadiums, the World Health Organization (WHO) said Thursday.
"We need to look much beyond just the stadia themselves," Catherine Smallwood, Senior Emergency Officer at WHO's European office, told a press conference when asked about recommendations in the face of rising cases in London and Saint Petersburg.
The British capital is due to host the semi-finals and final of the tournament next week, while the Russian city will host the quarter-final between Switzerland and Spain on Friday.
Asked about whether the Euro championship was potentially acting as a "super spreader" event, WHO regional director for Europe Hans Kluge replied: "I hope not... but this can't be excluded."
Hundreds of cases have been detected among spectators attending Euro matches, including Scots returning from London, Finns returning from Saint Petersburg and carriers of the more contagious Delta variant in Copenhagen.
"What we need to look at is around the stadia. How are people getting there? Are they travelling in large crowded convoys of buses? Are they taking individual measures when they are doing that?," Smallwood said.
She also added that it was also important to look at what was happening after the games, for instance if fans gathered in crowded bars.
"Should this mixing happen, there will be cases," she said.
The UN organisation also called for vigilance around all major summer gatherings, not just around football games.
"What we know is that in a context of increasing transmission, large mass gatherings can act as amplifiers in terms of transmission," Smallwood said.