Tens of thousands of yellow-shirted cyclists took over Bangkok's streets yesterday in honour of King Bhumibol Adulyadej, the world's longest-reigning monarch.
Led by Crown Prince Maha Vajiralongkorn, the tightly choreographed "Bike for Dad" event involved about 100,000 cyclists pedalling through a 29km route that passed key landmarks such as Chulalongkorn University and the commercial district at Ratchaprasong intersection.
Some schools were closed as the heir-apparent rode through streets lined with flag-waving crowds in the afternoon heat. Several people held aloft photographs of the King, who turned 88 last Saturday.
"This is my way of expressing love and gratitude to the King," said 67-year-old shopowner Samniang Techathanomkul, who turned up hours before the event on his bicycle. "He is the nation's father and we are here to show our respect as his children."
The ride was preceded by a massive publicity drive weeks before the day of the event. Advertisements in English and Chinese were circulated on TV networks, where news presenters wore a yellow-blue "Bike for Dad" outfit.
The kingdom's embassies abroad produced slick music vi-deos of cyclists wearing the official T-shirt and cruising by international landmarks. One featured Thais bowing to a portrait of the King against the backdrop of the Singapore Flyer and the skyscrapers hugging Marina Bay.
At the heavily guarded start point in Bangkok yesterday - where foreign diplomats were also present - government officials even gave out T-shirts to bystanders who happened to be wearing the wrong shade of yellow, the colour associated with the King.
Well-wishers who lined the pavements relished the rare chance to see the royal family up close. "I came here to greet the Crown Prince," said Ms Nakhemtamika Chanudonjiraphat, 45, a civil servant. "It's hot, but I am happy and willing to do this to show my support for the royal family."
Though Thailand is a constitutional monarchy, the King is seen as a unifying figure. Yet he did not appear in public nor release a statement on his birthday, even as anxious well-wishers camped out at Siriraj Hospital, where he is being monitored by doctors. In August, the palace revealed that he had been treated for fluid in his brain as well as chest infection.
The King's frail health and the impending royal transition are giving rise to much uncertainty and speculation. Most of such talk, however, is kept out of public earshot by the lese majeste law, under which those who defame or insult the monarchy can be jailed up to 15 years on each count.
Yesterday's royal mass cycling event was the second to be held. The first, held in August to celebrate Queen Sirikit's 83rd birthday, also featured the Crown Prince prominently.
Two months later, however, three individuals linked to the event were arrested for allegedly using the name of the monarchy for personal gain. Two have since died while under military custody.
The military has tightened its monitoring of social media for lese majeste infractions.This week, a man was arrested for "liking" a doctored photo of the King on Facebook and sharing it.