Protesters initially gathered at the Democracy Monument in Bangkok, which has been a meeting place during months of protests, while giving their three-finger salute — a popular symbol of the protests — on Wednesday.
“Down with dictatorship! Long live democracy!” the marchers chanted as they moved off from the monument and marched toward the government house.
The rally is the latest in three months of anti-government protests.
Earlier in the day, a group of people gathered just meters away in support of the country’s monarchy and the government.
A brief brawl occurred between the protesters and the royalists — all of whom were clad in the royal yellow color — before police intervened.