Berlin - German Chancellor Angela Merkel on Saturday condemned "in the strongest terms" the failed coup in Turkey, but called on President Recep Tayyip Erdogan to deal with the plotters lawfully.The treatment "of those responsible for the tragic events of last night can and should only be handled according to the rule of law," she said after the coup bid, which left more than 250 people dead.Erdogan, who flew back from the holiday resort of Marmaris to a triumphant welcome from supporters at Istanbul's Ataturk Airport, denounced the coup attempt as "treachery"."They will pay a heavy price for this act of treason," Erdogan said of the putschists. "We will not leave our country to occupiers."Prime Minister Binali Yildirim said the plotters were "cowards" who "would get what they deserve."Addressing Erdogan but not mentioning him by name, Merkel said that "democracy, which respects everybody's rights and protects minorities, is the best foundation [for the rule of law]".Germany stands by "all those who, in Turkey, defend democracy and the rule of law," she said, adding that political change should only take place through parliament.