Deputy Police Commissioner-General Pol Gen Somyos Pumpuangmuang visited the Ratchaprasong area at 10 am.
Seeing no protesters turning up, he ordered the number of troops to be reduced from nine companies to four and the number of police from four companies to three.
Somyos said he expected that the protesters would not turn up for a rally at the Intersection as planned.
Eight simultaneous rallies around Bangkok, including at Ratchaprasong, were announced by red-shirt activist and Laijut online magazine editor Sombat Boonngarmanong. Sombat himself did not turn up.