One hundred people were arrested in Barcelona, Spain, Saturday evening during widespread looting and riots across the city.

The hordes of mostly young men, many of them minors, were answering a social media call to act “against the system.” According to social media posts, the riots were inspired by the social unrest gripping France, as the posts used the phrase “institut indignats,” translated from the French “lyceéns indignés,” the phrase used in France on social media to rally high school students and which means “indignant high school students.”

Núria Parlon, the interior minister for ​the Spanish region of Catalonia, said that about a quarter of those arrested were minors and that rioters set more than 30 fires and looted at least 14 stores. Some people were trapped inside stores after they were shuttered against the rioters.

Barcelona Mayor Jaume Collboni warned that those involved would face legal consequences, including parents of rioting minors.