The new Peace and Order Maintaining Command (POMC) centre has shut down 14 satellite television stations, including Bluesky, ASTV and Asia Update.
An armed soldier stands guard in front of the offices of Voice TV on Vibhavadi Rangsit Road. Pornprom Sattrabhaya
The POMC said the stations had been closed until further notice "to ensure propagated news is accurate and not distorted".
Those shut down include pro- and anti-government stations. They are Bluesky, ASTV, Asia Update, MV 5, DNN, UDD, P&P, Four Channel, FM TV, TNews, Voice TV, Hot TV, Rescue, and Network of Students and People for Reform of Thailand (NSPRT).
The POMC has also ordered unlicensed community radio stations shut down.
It was also restricting comments on TV and in the print media by prohibiting remarks that could confuse society or provoke violence.
It said print media owners, television programmes, programme hosts and journalists must not let academics, former government officials or former judicial and independent organisation figures express opinions that worsen conflicts, distort information, or incite violence.
Violators would be prosecuted and distribution of offending editions and the broadcasting of programmes that transgress the order will be halted immediately, the POMC warned.
Gen Prayuth had earlier met media representatives and government officials at the Army Club on Vibhavadi Rangsit Road. He told them that mainstream media outlets would not come under pressure and they should not worry about the imposition of martial law.
"Some TV stations have been ordered to halt broadcasts to maintain peace and order in the country," he said.
Soldiers were yesterday deployed at all television stations after martial law was imposed. Soldiers from the 19th Infantry Battalion took control of the Thaicom satellite base station in Nonthaburi and Channel 11 TV at the Public Relations Department on Vibhavadi Rangsit Road.
Time Chuastapanasiri, a researcher at the Academic Institute of Public Media, called on the army not to shut down TV stations for more than three days, or risk a barrage of public criticism about media freedom.