Since seizing power last week the military has summoned more than 250 people, curtailed liberties under martial law and imposed a nightly curfew as part of a series of measures that have sparked dismay among rights groups.
Analysts say the move to detain political figures from across the kingdom's bitter divide is aimed at quelling potential opposition to the May 22 coup.
After an outcry on the Internet, the army interrupted national television to deny it had blocked Facebook after the site briefly went down and caused panic online.
Some users were unconvinced with the junta's denial, speculating that it could have been a trial run for a possible blackout in the future, or a warning shot to social media users not to criticise the coup.
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Social media platforms such as Twitter and Facebook are hugely popular in the country, and have been used by anti-coup protesters to organise small protests against the military regime.
Despite warnings by the army of a widening crackdown on dissent, protesters have been gathering in Bangkok in small but vehement rallies against the military takeover, while rival pro-coup rallies have also sprung up.
The movement's chairman Jatuporn Prompan said they were "treated well".
"What we have been most concerned about is that the losses (of life) in 2010 should not happen again in 2014 -- we should learn the lessons," he said, referring to a bloody military crackdown on their rallies against a previous government that left dozens dead.
The army has said people who have been detained and released since the coup must sign a document promising to cease political activity.