On 22 June 1941, during Operation Barbarossa, most of the houses of Wizna's 600 Jews were burned down following an aerial bombardment. Five German soldiers arrived on 24 June 1941, and local Poles killed three Jews on the same day. Jews fled the town, and local Polish collaborators searched for them in the surrounding villages and turned them over to the Germans after beating up the Jews and their Polish helpers. On 26 June, local Poles locked 20 Jews up in a smithy and a German threw in hand grenades, killing them all. Most of the town's Jews returned by early July, and dozens were killed by the Germans. The Polish mayor ordered the expulsion of the Jews, due to the lack of housing, some traveled to Łomża and some 200-240 traveled to Jedwabne where many perished on 10 July 1941 in the Jedwabne pogrom.