Several hours after the attack, police cornered the suspect and more shots were fired. The counter-terrorism prosecutor has opened an investigation. French Interior Minister Christophe Castaner said the gunman was known to security services, and the local prefecture said he was on an intelligence services watchlist.

People in the city's Neudorf and Etoile park area were told to stay where they were as officers hunted the shooter on the ground and from the air. The European Parliament, which is sitting in Strasbourg this week, was placed on lockdown.