Moscow on Wednesday called for Ankara to arrest a Turkmen fighter it claims killed the pilot of the Russian jet downed by Turkey for airspace violation last month. "We demand that the Turkish authorities take immediate steps to apprehend Alparslan Çelik and his accomplices and bring them to justice for the murder of the Russian pilot," foreign ministry spokeswoman Maria Zakharova said in a statement. In an interview published Sunday in Turkish newspaper Hürriyet, Çelik -- a Turkmen rebel and citizen of Turkey -- said that his "conscience cannot be bothered by a person who threw bombs at Turkmen civilians every day," referring to the slain Russian pilot.Both pilots aboard the downed Su-24 jet ejected and parachuted to the ground on the Syrian side of the border, one of whom was killed by gun fire from the ground."Revenge is the most natural right," Çelik said in the interview, while refraining from claiming the pilot's death.Moscow and Ankara have been locked in a bitter spat over the downing of the Su-24 jet on November 24, with the Kremlin imposing a raft of economic sanctions against Turkey.Zakharova said that the publication of Çelik's comments in a major Turkish newspaper had angered and surprised Moscow.She added that Çelik's comments constituted an admission of his "direct involvement in the murder of the Russian pilot".Turkish authorities have accused Russia of "ethnic cleansing" in Syria, targeting Turkmen and Sunni population that oppose the regime of Syria's Bashar al-Assad, Moscow's long-time ally. According to U.K.-based monitoring group Syrian Observatory for Human Rights, over one third of those killed in three months of Russian airstrikes in Syria have been civilians.On November 24, two Turkish F-16 fighter jets on an aerial patrol intercepted a Russian warplane within rules of engagement when it violated Turkish airspace near the Syrian border.The Russian warplane received 10 warnings about its violation within five minutes before it was shot down. This was not the first time Russian warplanes had violated Turkish airspace. In October, Russian warplanes violated Turkish airspace. Russian officials had apologized and pledged that such incidents would not reoccur in the future.