ANKARA (AFP) - Turkish Prime Minister Recep Tayyip Erdogan issued the first official apology on Wednesday for a bloody military campaign that killed thousands of Kurds in southeast Turkey at the end of the 1930s. "If it is necessary to apologise on behalf of the state... I will apologise, I am apologising," Erdogan told his Justice and Development Party (AKP) members in Ankara in televised remarks. Erdogan said the air strikes and ground operations in the city of Dersim -- now named Tunceli -- killed 13,800 people between 1936 and 1939, according to an official document of the time he cited in his speech. The offensive took place under the rule of the current main opposition Republican People's Party (CHP), which was established by Mustafa Kemal Ataturk, the founder of the modern Turkish state. Some 11,600 people were exiled to other regions across Turkey, Erdogan said, citing another official document signed by Ismet Inonu, then leader of the CHP and Turkey's second president after Ataturk died in 1938. Turkey was under one-party rule of the CHP until 1946. Erdogan said the archives of his office were open for any research of official documents about the events. "Dersim is one of the most tragic events of our near history. It is a disaster waiting to be enlightened and boldly questioned," Erdogan said. The strikes targeting Dersim were tried to be legitimised as "quelling an uprising," Erdogan said, but "there was an operation which was planned step by step." Erdogan slammed the CHP for the killings and urged the party to "face" that bloody campaign. The current leader of the CHP, Kemal Kilicdaroglu, is from Dersim. "Dersim is the most painful and bloody (event) among tens, hundreds of disasters the CHP had caused. It is not the AK Party and the AK Party government that should face this event and apologise, but it is the CHP," he said. Recently Mehmet Metiner, an AKP deputy, proposed changing the name of Sabiha Gokcen Airport in Istanbul, which was named after the adopted daughter of Ataturk. Gokcen was Turkey's first woman pilot and actively took part in the air campaign against Dersim. While Turkey is breaking a taboo on its official rhetoric about the Dersim killings, the country rejects Armenian claims of genocide at the hands of the Ottoman Empire during World War I years. Armenians say that up to 1.5 million of their kin fell victim to genocide in 1915, when the Armenian community across the country was driven from their homes. Turkey refuses to categorise the 1915 killings as genocide and counters that 300,000 to 500,000 Armenians and at least as many Turks died in civil strife when Armenians rose up against their Ottoman rulers and sided with invading Russian forces. Ankara is still battling Kurdish separatists, whose Kurdistan Workers' Party (PKK) took up arms for Kurdish independence in southeastern Turkey in 1984, sparking a conflict that has claimed some 45,000 lives.