Police said on Tuesday night that they have arrested two men on suspicion of "doing an act or acts with seditious intention."
Investigators alleged that the men, aged 18 and 29, are suspected of publishing social media posts to spread messages that promote feelings of ill-will and enmity between different classes of the population and incite the use of violence.
They added that officers had seized some electronic communication devices from the men's homes.
They said the men were separately arrested in Kwai Tsing and Sham Shui Po and are being detained for further investigation.