In a Facebook Live broadcast, Arnon called on pro-democracy groups to gather outside the centre in downtown Bangkok on Wednesday from 6pm onwards.
His announcement came after prominent activist Jatupat “Pai Dao Din” Boonpattararaksa was arrested along with 20 other protesters who participated in small rally at Democracy Monument ahead of the main event on Wednesday.
Jatupat had led protesters from his home province of Khon Kaen to gather on Ratchadamoen Road, where a Royal motorcade was scheduled to pass later in the day.
Protesters said police used the upcoming motorcade to justify the arrests.
All detainees have been put behind bars at the Border Patrol Police Region 1 headquarters in Pathum Thani province, north of Bangkok.
In response to Arnon's announcement, pro-democracy protesters began gathering at the Skywalk in front of Bangkok Art and Culture Centre before student leader Parit "Penguin" Chiwarak led the crowd to the National Police Headquarters nearby .
Protest leaders wrapped up the rally outside the National Police Headquarters at 8.40pm and called on pro-democracy groups to gather at Democracy Monument at 2pm on Wednesday.