0340 GMT October 24, 2020
The youth-led movement has suffered several blows this week, with scores arrested after demonstrators surrounded a royal motorcade and flashed a pro-democracy salute to Queen Suthida during a Wednesday protest, AFP wrote.
The government reacted by imposing "serious" emergency measures banning gatherings of more than four and allowing for the arrest of protest leaders, many of whom are calling for the removal of Prime Minister Prayuth Chan-ocha, a former military chief first came to power in a 2014 coup.
Police also deployed water cannon against unarmed demonstrators on Friday in Bangkok's central shopping district in an escalation of tactics that drew outrage across Thai society.
But the crackdown has emboldened the movement's mostly young supporters who have turned up in large numbers to daily guerrilla protests around Bangkok.
The locations are announced an hour before to outwit authorities, who shut down much of the city's Skytrain and underground rail services to discourage people from joining in.
Thousands descended on the major traffic thoroughfare shouting "Free our friends" while carrying posters of arrested activists.
Among their demands is the abolition of a draconian royal defamation law – which shields King Maha Vajiralongkorn from criticism – and a call for the monarch to stay out of the country's turbulent politics.
Once-taboo in Thailand, the issue of royal reform demanded by protesters is one of the biggest challenges facing the kingdom's military-aligned government.
The social media-savvy protesters have also harnessed unorthodox ways of spreading their messages, sending alerts through newly formed groups on Telegram – a secure messaging app – and taken tips from Hong Kong's protests.
Across town in Asok, a popular shopping and restaurant district, a smaller group of protesters gathered and practiced hand signals to warn each other if authorities were to issue another severe crackdown.
National Police spokesman Yingyos Thepjumnong warned protesters earlier Sunday that no rallies "causing unrest and disorder" would be allowed.
"If they defy it, police will do whatever is necessary to enforce the law," he said.