The coronavirus (COVID-19) is spreading during hobby activities such as in choirs, children's groups and at sports training. The Health Board is recommending that groups in Tallinn, Harju County and Ida-Viru County suspend activities or move to distance learning.
More than 10 outbreaks have occurred at similar clubs and more than 100 people are infected.
To ERR's knowledge, one of the biggest outbreaks is currently associated with Ellerhein Choir but the virus is also spreading in school choirs and to both children and teachers. An outbreak also started at a pensioners' choir in Ida-Viru County and several events in Hiiu County.
Eike Kingsepp, a spokesperson for the Health Board said: "Singing is, yes, a dangerous activity." This is because the activity causes the virus to spread around the room, which is usually an enclosed space.
"We are seeing that a lot of infections come from hobbies: children's groups, sports training, etc.," Kingsepp said.
The was also an outbreak at a hockey game in Narva which then spread the virus to schools. As a result, several schools in the city have moved to distance learning.
Editor: Helen Wright