Many German-inspired massacres were carried out across occupied eastern Poland with the active participation of indigenous people. The guidelines for such massacres were formulated by Reinhard Heydrich, who ordered his officers to induce anti-Jewish pogroms on territories newly occupied by the German forces. In the lead-up to the establishment of the Wilno Ghetto in the fifth largest city of prewar Poland and a provincial capital Wilno (now Vilnius, Lithuania), German commandos and the Lithuanian Auxiliary Police Battalions killed more than 21,000 Jews during the Ponary massacre in late 1941. At that time, Wilno had only a small Lithuanian-speaking minority of about 6 percent of the city's population. In the series of Lviv pogroms committed by the Ukrainian militants in the eastern city of Lwów (now Lviv, Ukraine), some 6,000 Polish Jews were murdered in the streets between June 30 and July 29, 1941, on top of 3,000 arrests and mass shootings by "Einsatzgruppe C". The Ukrainian militias formed by OUN with the blessings of the SS spread terror across dozens of locations throughout south-eastern Poland.