The Southeast Asian Games officially opened on Thursday and Thailand continued its early dominance in events preceding the ceremony.

Thailand extended its lead atop the medal standings for the 24th SEA Games, taking its gold medal tally to 21 with victories in mountain biking and sepak takraw on Thursday. Singapore is second with 10 golds. Burma has so far won two silver medals.

The opening ceremony centered on honoring Thailand's King Bhumibol Adulyadej, who turned 80 on Wednesday. His son, Crown Prince Maha Vajiralongkorn, presided over the ceremony in which the Thai team and much of the crowd wore yellow, the monarch's traditional color.

The SEA Games flame was carried into the stadium by 2004 Olympic boxing bronze medalist Suriya Prasathinphimai, but appeared to go out just as he handed it to 2004 Olympic weightlifting gold medalist Udomporn Polsak.

After switching torches mid-route, Udomporn lit a SEA Games emblem which was then transported by wire above the stadium to set off a spectacular fireworks display.

A large banner with the words "Save the World" was also pulled across to the entire infield where the teams were gathered, as organizers pledged to stage environmentally friendly games and tackle climate change.

Burma claimed silver medals in the men's and women's hoop sepak takraw events, in which Thailand won gold.

The sepak takraw competition was been the subject of early controversy at the games after perennial powerhouse Malaysia pulled out in protest at the use of a rubber-coated ball rather than the traditional rattan ball.