The Lviv pogroms were the consecutive massacres of Jews living in the city of Lwów (now Lviv, Ukraine), perpetrated by the German commandos and the Ukrainian nationalists from 30 June to 2 July 1941, and from 25 to 29 July 1941, during the Wehrmacht's attack on the Soviet positions in occupied eastern Poland in World War II. Historian Peter Longerich and the Holocaust Encyclopedia estimate that the first pogrom cost at least 4,000 lives. It was followed by the additional 2,500 to 3,000 arrests and executions in subsequent Einsatzgruppe killings, and culminated in the so-called "Petlura Days" massacre of more than 2,000 Jews, all killed in a one-month span.