France's home Six Nations match against Ireland on Saturday has been postponed due to the coronavirus, organisers said on Monday.
The Stade de France fixture becomes the third game of this year's tournament to be called off after Italy and England in Rome and Ireland v Italy in Dublin. No date has been fixed for playing the postponed matches.
The French government banned all public gatherings of more than 1,000 people late Sunday in a bid to slow the spread of Covid-19 which has infected 1,100 people and killed 19 in the country.
"Following instructions received from the authorities in France, the decision has been made to postpone the Round 5 Six Nations match between France and Ireland," organiser Six Nations Rugby said in a statement.
The decision means that Saturday's Wales v Scotland match in Cardiff is the only remaining match on the Six Nations programme, leaving the tournament unfinished with the identity of the champions uncertain.
A similar situation arose in 2001 when the series was interrupted and three matches were postponed by a foot-and-mouth outbreak in Britain when fans had to wait until October to see England crowned champions.
England, following their win over Wales on Saturday, top the table as it now stands with 13 points.
France are in second place, also on 13, but with an inferior points difference, after losing Sunday's game against Scotland at Murrayfield 28-17 which ended their hopes of a Grand Slam.