The "gilets jaunes" or "yellow vests" protesters clashed with French police in Nantes on Saturday. The movement brought some French towns to a standstill earlier this year.
After the body of a man who went missing during a police operation at France's Fete de la Musique last month was found on Tuesday, people took to social media to demand answers.
It's unclear at this stage whether the body is that of Sala or the pilot of the aircraft.
Nantes supporters staged a tearful and at times noisy vigil for former player Emiliano Sala on Tuesday after the plane carrying him to new club Cardiff City disappeared over the Channel.