After a hard fight the French troops in the Lille pocket finally surrendered on the 1st of June 1940. In this photo, a column of French POWs marches past the dead crew of this anti-tank guns who gave their all in a desperate last stand for France. Rue de Solferino, Lille.
The guns appear to be French "Canon de 25" (canon de 25 mm semi-automatique modèle 1934). This Hotchkiss product was by a long chalk the most common antitank gun in the French Army in 1940. Some units had the excellent (for this date) 47mm 47 SA 37, but this gun was rare among general antitank units. As far as I can see, priority was given to tank mounting of the 47mm (much to the discomfiture of the Panzers during the Battle of France), leaving the general AT units dependent on the 25mm.
The latter was effective against PzKpfw I and II at reasonable range, but proved to be ineffective against heavier German tanks except at very close range. By the time of the surrender of Lille, the Germans were fully alive to the need to shield their vulnerable light tanks with their limited number of PzKpfw III and (more effectively) PzKpfw IV in engagements against the better French tanks, and against antitank units. This meant that for a French antitank unit armed with 25mms, near-suicidal bravery was required to take a stand against a German tank attack. These must have been brave men. They deserved better than this. Rest in Peace. JR.