The 2013 World Taekwondo Championships opened on Sunday night at the exhibition center in Central Mexico\'s city of Puebla, with the participation of 872 athletes from 134 countries and regions and more than 5,000 local audiences. The opening ceremony started with folk dances that showed the legend of Popocatepetl, which is an active volcano located in the states of Puebla and the second highest peak in Mexico, and considered as the \"faithful guardian of Puebla.\" Puebla State Governor Rafael Moreno Valle and the president of the World Taekwondo Federation (WTF), Choue Chung-won, opened the biennial Championships, which are scheduled for July 15-21. Choue thanked the Organizing Committee of Puebla for agreeing to host the 2013 World Championships. He said that Puebla will hold the best championships ever seen in history, highlighting the state government\'s performance in the preparation of this tournament and ensured that taekwondo has been more successful than ever. \"Dear athletes, please train hard and compete fairly, to show the audience of Puebla, Mexico and the whole world how wonderful is taekwondo,\" he said. For his part, Valle thanked Mexican President Enrique Pena Nieto for his support in organizing the tournament. He also highlighted the work realized by various levels of state government for the great event. \"The hope for your countries lies with you, let\'s work together to make this championship the best in the world,\" said the governor to the athletes, encouraging them to compete for the titles. For the Puebla Championships, the 21st edition of its kind for men and 14th for women, a total of 134 countries and regions submitted their entry forms involving 872 athletes to the WTF. The previous World Taekwondo Championships were held in Gyeongju, South Korea in 2011, attracting 950 athletes from a record 149 countries and regions on an entry basis. According to the WTF, the championships will feature eight male and eight female weight categories: -54kg, -58kg, -63kg, -68kg, -74kg, -80kg, -87kg and +87kg for men, and -46kg, -49kg, -53kg, -57kg, -62kg, -67kg, -73kg and +73kg for women. The Chinese delegation, headed by world champions Hou Yuzhuo and Zhang Hua, will participate in all the 16 categories during the championships. A total of 100 international referees will officiate at the seven-day championships. To ensure fair judging at the championships, a Daedo protector and scoring system (PSS) will be used together with an instant video replay system. One center court will be used for semifinal and final matches, while five courts will be used for other matches. From: XINHUA