Three women and a man were charged on Friday for sharing a doctored nude photo of Senegalese President Macky Sall via WhatsApp.
The four were jailed in Dakar after a judge charged them with sharing an offensive image and criminal conspiracy.
Media reports say the police is looking for a fifth person in Gambia who allegedly sent the image through the messaging application.
According to the media, the police were notified of the doctored photo by a member of the WhatsApp group.
In Senegal, a sender of an offensive image can be jailed for one to two years with a potential fine of over $500.
The arrests come at a time when the country is preparing for polls on July 30.
Senegal is considered to be one of the most stable democracies in Africa.