Senior Fifa officials have been detained in morning raids on a Zurich hotel, accused of accepting millions of dollars in bribes.
US officials targeted current and former high-ranking Fifa directors at the luxury Baur au Lac hotel as part of the Department of Justice's investigation into corruption at the heart of world football.
The arrests arrive as Fifa's executive committee begins two days of meetings to discuss reforms.
Fifa vice-presidents Alfredo Hawit and Juan Angel Napout, heads of the Central American and South American football associations respectively, are among those arrested according to reports.
Up to 16 people are expected to eventually be charged by the DoJ, who arrested seven Fifa officials at the same location in May.
"Fifa became aware of the actions taken today by the US Department of Justice," the world football governing body said in a statement.
"Fifa will continue to co-operate fully with the US investigation as permitted by Swiss law, as well as with the investigation being led by the Swiss Office of the Attorney General."