Two soccer matches in Mexico City will be played behind closed doors due to a deadly outbreak of a previously unknown strain of flu in the country, the Mexican Football Federation said on Friday.
Guadalajara and America, Mexico's most popular teams, will play Pumas and Tecos respectively in league matches on Sunday - but normally packed spectator stands will be empty.
"This decision is being taken with the full awareness of the clubs to comply with the measures implemented by the health authorities," the federation said in a statement.
The Mexican government said at least 20 people have died of the virus, a type of swine flu, and it may also be responsible for 48 other deaths. It said 1,004 suspected cases have been reported so far.