 In 1992, however, Turkey, backed by United States and Peshmergas of Kurdistan Democratic Party and Patriotic Union of Kurdistan, launched Operation Northern Iraq, a cross-border operation between 9 October and 1 November against the PKK using more than 300,000 troops.Thousands of local Peshmergas with the support of more than 20,000 Turkish troops who had crossed the Iraqi border, tried to drive 10,000 PKK guerrillas from Northern Iraq.Despite the heavy casualties, the PKK managed to maintain its presence in Northern Iraq and a cease fire agreement was reached between the PKK and KRG.