International Olympic Committee (IOC) president Thomas Bach hailed "a really fantastic Youth Olympic Games" as Buenos Aires 2018 officially came to an end.The closing ceremony at the Youth Olympic village on Thursday broke with tradition by eschewing long official speeches and the usual athletes parade, reports Xinhua news agency.There were still acrobats, tango dancers, a flags parade and a rousing rendition of Argentina's national anthem.It also featured the handover of the Olympic flag to Soham El Wardini, the mayor of Senegal's capital Dakar, which will host the next summer Youth Olympics in 2022.The Olympic cauldron was then extinguished before a spectacular fireworks display brought the 45-minute show to an end."We have been celebrating together a great festival of sports and I have enjoyed watching you," Bach told the large congregation of athletes who gathered for the ceremony."Thank you for your great performance, your fair play and your Olympic spirit. You really were the best."Buenos Aires 2018 President and IOC member Gerardo Werthein also paid tribute to the 4,000 athletes from 206 countries and regions who took part in the Games, as well as the thousands of volunteers."You honoured my country... I want to thank all the team at the IOC, headed by Thomas Bach, for all the support and for giving us the opportunity to do something different," Werthein said.Russia was the most successful delegation at Buenos Aires 2018 with 29 gold medals, followed by China (18), Japan (15), Mixed NOCs (13), Hungary (12), Italy (11) and Argentina (11).