The Dutch, Spanish and Monaco Grands Prix have been postponed due to the coronavirus outbreak, Formula 1 bosses have announced.
The first four races in Australia, Bahrain, Vietnam and China had already been called off due to the pandemic.
The sport’s governing body, the FIA, says it expects the 2020 season to begin “as soon as it is safe to do so after May”.
And it will look at “potential alternative dates later in the year”.
In a joint statement with F1 and the race promoters, it said decisions were taken “to ensure the health and safety of travelling staff, participants and fans”.
The decision comes at the end of a seismic week of developments in F1.
The season-opening Australian Grand Prix last weekend had to be called off after a McLaren team member tested positive for coronavirus in Melbourne and a total of 16 members of that team had to go into quarantine.
The decision to call off the following races in Bahrain and Vietnam followed within a few hours, while the Chinese Grand Prix had already been postponed in February following the virus outbreak in that country.
Since then, the sport has shifted its “summer break” forward to March and April to free up time to fit as many races into this year as possible once the season can resume, and the teams, F1 and the FIA have agreed to delay the introduction of a major set of rule changes by a year until 2022 to keep costs down.
A year has to have a minimum of eight Grands Prix to count as a world championship.
F1 has a working plan to try to start the season with the Azerbaijan Grand Prix on 7 June, but this may not be possible given the rapidly escalating coronavirus problem around the world.
Bosses are considering all possibilities – it is likely races will be run on a number of consecutive weekends, and be grouped together geographically as much as possible to facilitate that approach.
And some races are more likely than others to fall by the wayside as the calendar shifts.
The most vulnerable are the Monaco, Spanish, Brazilian, Chinese and Australian Grands Prix.