By Juarawee Kittisilpa, Patpicha Tanakasempipat and Chayut Setboonsarng
BANGKOK (Reuters) - "They think arresting the leaders will stop us. It's no use. We are all leaders today," 24-year-old Pla said as she addressed thousands of protesters at Bangkok's Victory Monument on Sunday.
Despite the arrest of many of Thailand's most high profile protest leaders over the past week, demonstrations have grown, with ever louder calls for the ousting of Prime Minister Prayuth Chan-ocha and reforms to King Maha Vajiralongkorn's monarchy.
Partly borrowing from the Hong Kong protest playbook and partly working things out for themselves, previously unknown protesters have thwarted police efforts and demonstrated the greatest public support for change in decades.
It was designed that way.
"Get your megaphones ready, your protective gear on, because everybody is a leader," the Free Youth group protest announced in a Facebook post on Sunday.
Before he was arrested on Saturday, well-known face Panupong "Mike Rayong" Jadnok, 24, sent the same signal by using the hashtag #everybodyisaleader on Facebook.
Even the sites for protests have been decided through votes on social media groups. Multiple announcements of possible protest sites have left police guessing. By the time they show up, thousands of people have already massed.
Police spokesman Kissana Phathanacharoen described the situation as "very dynamic", adding: "What we can say now is warn the public that they have to follow the law."
The lack of leadership on the ground caused some awkward moments on Saturday when people appeared unsure who should speak. Protests in Thailand traditionally involve a series of speakers on a stage.
Suthida "Smile" Buakhom, 20, stepped up at one rally with a microphone she had brought in the expectation it might be needed because of the arrests of dozens of activists.
"I know that people cannot stay in a place for long without some sort of focus," she told Reuters. "I try to encourage everyone to rise up to speak."
HONG KONG MODEL
Thai protesters have been quick to adopt the "Be Water" tactics of Hong Kong protesters, but have also got moral support from activists there who see a comparable struggle with an authoritarian system. Thai protesters seek to oust Prayuth, a former junta leader, and to reduce the monarchy's powers.
"Be kind to your fellows, have faith in collective wisdom, be fluid on strategies, be determined in actions," tweeted Hong Kong activist Nathan Law on Sunday in support of Thai protesters. "Never lose hope, stay safe."
Some 13 activists who met for the first time at Bangkok's Asok intersection on Sunday debriefed each other after the crowd of thousands dispersed peacefully - agreeing on a new chat group to keep in touch to prepare for future demonstrations.
"I came today to help with the organization but when I arrived there was no natural leader yet so I just started speaking," said Omyim, who gave only her nickname.
One of those who came forward, PK, was older than others at 30 and helped to ensure security - with everyone worried that police could again use water cannon and batons as they did at a protest on Friday.
"We need to protect the activists, especially the younger protesters," he told Reuters. He and other protesters had linked arms to separate the protest area from traffic and ensured people had the space to move.
Activists taught each other hand signals: "Danger", "Safe", "Someone has been Arrested", "Can't Hear", "Need Water" and more.
As word spread that police might approach the different demonstrations, human chains linked up to pass along protective gear such as helmets, goggles and umbrellas.
And beyond the immediate concerns for security, social media accounts sprang up to indicate where protesters could find toilets, where they might find missing friends or belongings or if they needed a bed for the night.
One student leader who gained prominence during earlier protests said she was leaving the spotlight, having so far avoided arrest.
"Now I'm just one of the people who want to see change alongside everyone," Chonthicha 'Lookkate' Jangrew, 27, told Reuters.
(Additional reporting by Jiraporn Kuhakan; Writing by Matthew Tostevin; Editing by Frances Kerry)