As the Partisans neared, Luburić suggested that the Ustaše make their last stand in Zagreb, but Pavelić refused. The Ustaše were divided as to what to do. Some proposed retreating towards Austria as quickly as possible. Others, Luburić foremost among them, advocated establishing irregular formations in the countryside that would carry out guerrilla attacks following the NDH's demise. In early May, Luburić met with the Archbishop of Zagreb, Aloysius Stepinac, who implored him not to put up armed resistance against the Partisans. On 5 May, the government of the NDH left Zagreb, followed by Pavelić. By 15 May, the NDH had completely collapsed. Tens of thousands of Ustaše surrendered to the British Army but were handed back to the Partisans. An untold number were killed in subsequent Partisan reprisal killings, together with several thousand Serbian and Slovenian collaborationists.