Riot police ended a protest by a small group of demonstrators who tried to occupy a section of Ratchadamnoen Avenue on Tuesday ahead of their main rally there that could stand in the way of a royal motorcade on Wednesday.
The group of about 30 demonstrators set up their tents on Ratchadamnoen Avenue near the Democracy Monument on Tuesday morning.
In the afternoon, their leaders delivered speeches as followers confronted police who were trying to convince them to leave.
A motorcade of His Majesty the King would reportedly pass the avenue heading for the Temple of the Emerald Buddha for a graduation ceremony of Pali scholars on Wednesday.
At about 1.30pm Pol Maj Gen Methee Rakphan, commander of the Metropolitan Police Division 6, and police from the Samranrat station arrived at the site to ask demonstrators to leave but to no avail.
Demonstrators and their leaders played music, sang and danced while police asked them through loudspeakers to step out of the road surface to end traffic blockage. Mr Jatupat "Pai Daodin" Boonpatararaksa then told followers to sit down.
At 3pm, police again asked the demonstrators to leave. As Mr Jatupat resisted, about five companies of riot police were deployed. Some demonstrators splashed blue paint at them.
The leaders, including Mr Jatupat, and the demonstrators were arrested and brought out of the rally venue at about 4pm.
Among arrested demonstrators, singer Chaiamorn Kaewwiboonpan, aka Ammy The Bottom Blues, asked on his Facebook page that demonstrators should massively show up on Wednesday.
Deputy police spokesman Pol Col Kissana Phathanacharoen said 19 demonstrators were arrested for many offences, including the unauthorised organisation of a rally. They were detained at the Border Patrol Police Region 1 in Pathum Thani province.
An official cleans blue paint of demonstrators from Ratchadamnoen Avenue after the demonstration crackdown. (Photo by Pornprom Satrabhaya)