Police fired tear gas at protesters for a second day on Monday as they tried to force their way into Government House and the Metropolitan police bureau.
The confrontation took place in the morning near the barriers on Chamai Maruchet bridge on Phitsanulok Road, which leads to the Government House.
Some of the protesters were those from the Rajadamnoen rally site.
Police fired the tear gas and smoke bombs at the protesters. They were seen dispersing and covering their faces. After pouring water on themselves, many of them returned to the front line.
Many of the protesters wore raincoats and plastic bags over their heads, to protect against the sting of tear gas.
The Democrat-affiliated Blue Sky channel broadcast the attacks live, showing the police repeatedly fired the tear gas and smoke bombs at the protesters. Reports also indicated that rubber bullets had been used.