There were no reports of clashes in a "softly softly" operation that appeared designed to test the strength of the dwindling bands of anti-government protesters who have been disrupting life in the Thai capital since November.
Police pulled back from confrontation with protesters after a stand-off at one site and made no move against the largest sites at road junctions in the city's main shopping and business districts.
National police chief Adul Saengsingkaew said: "Our strategy is to do this slowly and work inwards from areas outside of central Bangkok towards the main protest sites.
"We are not dispersing the protesters or using force, we are using negotiations as our main tactic."
Protesters want to oust Ms Yingluck, who they claim acts as a proxy for her brother, Thaksin Shinawatra.