The Associated Press news agency has analysed protests over the past few days and found that demostrations over the killing of George Floyd had been held in every one of the 25 US communities with the highest concentrations of new cases.
There are growing fears that the tightly packed streets and squares with people often not even wearing any face masks could lead to a spike in the number of new cases.
There are currently 1.8 million confirmed cases of coronavirus in the US - with more than 106,000 deaths.
In the US, the country with the world’s highest coronavirus death toll, local state and city officials warned that the public gatherings in the countrywide protests sparked by the police killing of George Floyd in Minneapolis risked triggering even more infections, with some testing centres being closed because of the protests.
Among them, the Minnesota governor, Tim Walz, warned that hospitals were “on the verge of being overrun”, adding that “demonstrators should wear masks and try to practice social distancing”, while the Los Angeles mayor, Eric Garcetti, said all coronavirus testing centres across the city had closed on Saturday because of safety concerns.
Keisha Lance Bottoms, the mayor of Atlanta, also suggested those attending demonstrations should seek a test for Covid-19.
The pandemic has provoked differing approaches from politicians and public health authorities around the world, not only over the response during the period of peak infections but also over how to ease their lockdowns.