Police fired tear gas as protesters rallied outside Pathumwan police station in Bangkok after some were arrested during a rally at Pathumwan intersection.
The demonstrators gathered outside the police station after marching from the rally at the downtown intersection in the biggest pro-democracy rally this year so far.
Police arrested 10 people at Pathuwan intersection. Some were later released.
Protest leader Panusaya "Rung" Sithijirawattanakul announced the march and led the rally to the police station, which is about one kilometre away.
The rally was held for the second day after the Criminal Court denied bail to four key members facing royal insult charges. They were Anon Nampa, Parit “Penguin” Chiwarak, Somyot Prueksakasemsuk and Patiwat “Mor Lam Bank” Saraiyaem.
Pol Maj Gen Piya Tawichai, the Metropolitan Police Bureau deputy commissioner, warned on Wednesday that the rally violated the emergency decree as the gathering could spread the coronavirus.
Panupong Jadnok, another protest leader, said the detention of the four activists at Bangkok Remand Prison on Tuesday will not affect demonstrations.
Ms Panusaya announced the end of the rally at around 9pm after all protesters detained earlier had been released.