The Czech Republic expels 18 Russian diplomats after linking the operatives to a 2014 explosion.
Some cases of the Indian variant have been found that are not linked to travel, a scientist says.
Ticket-holders for the outdoor concert in Liverpool will have to provide a negative test beforehand.
Leaders of the UK's biggest hospitality firms sign an open letter to Prime Minister Boris Johnson.
Millions more around the world watch the service across online channels, including YouTube.