Hundreds of Thai anti-government protesters entered the police headquarters in Bangkok on Wednesday to present their grievances.
They met no opposition as they cut the locks on the gates and pulled down barricades to gain access.
The demonstrators handed over a letter to police detailing their complaints. They then left the compound.
The peaceful assault came during a lull in violence in the Thai capital , a day after Prime Minister Yingluck Shinawatra ordered police to end their resistance against crowds who had been trying to storm her offices.
At least five people have been killed and more than 250 wounded during days of violence sparked by the protests.
The truce is expected to last until after revered King Bhumibol Adulyadej’s 86th birthday on December 5.
But protest leaders have vowed to keep up their struggle to overthrow Yingluck Shinawatra and prevent her brother, deposed former Prime Minister Thaksin Shinawatra, from having any influence.