The first clash happened at Makawan Rangsan Bridge at about 9am when the protesters tried to march through the police barricade to join the rally at the Royal Plaza.
They refused to make a detour to the Wat Benjama Intersection and First Division Intersection, where police allowed the demonstrators to pass through.
So police fired teargas at the advancing protesters, resulting in a clash.
At this spot, police arrested 132 protesters. One of them was a TV cameraman, who was later released after other newsmen informed police that he was on duty.
Police searched the arrested protesters and found knives, some bullets and slingshots.
Four protesters were reportedly injured from the tear gas.
In the second clash, Police fired teargas at protesters at the Miskawan Intersection to try to prevent them from breaking through police barricade at the Miskawan Intersection at about 10 am.