Thailand's military has ordered 35 more people, including prominent academics, to report to them by Saturday afternoon as the post-coup crackdown continues.
The move comes a day after the army ordered more than 100 politicians, including ex-PM Yingluck Shinawatra, to come to the military council.
Ms Yingluck was detained in Bangkok on Friday and spent the night in custody.
Many on the army's latest list have previously been charged with speaking or acting against the monarchy.
Meanwhile, several hundred protesters have taken to the streets of Bangkok to show their anger at military's seizure of power, defying a ban on large gatherings.
Anti-coup banners were unfurled as they arrived at Victory Monument.
Officials said the former prime minister would not be held for more than a week but insisted that her detention was necessary while matters in the country were "organised".
Ms Yingluck, who had been PM until being removed by the judiciary this month, was ordered to report to the military along with more than 100 other politicians, including acting PM Niwatthamrong Boonsongphaisan.
Thai military spokesman Col Werachon Sukhondhadhpatipak said on Saturday that the politicians had been detained to give them "time to think".
He refused to reveal where the detained were being held and said that their mobile phones had been confiscated.
Col Werachon said those detained were being encouraged "to find common ground" and that the army wanted "to change their perception."
Despite the detentions, the leader of Ms Yingluck's Pheu Thai party, Charupong Ruangsuwan, was quoted as saying he would not surrender to the military authorities.
The military spokesman said those named on the new list had until 13:00 local time (06:00 GMT) on Saturday to report to the army.
Among the 35 names are a diverse collection of academics, politicians and activists, including:
- Several prominent figures in the pro-government Red Shirts movement
- A former national police chief and a serving provincial police commissioner
- An MP from the Pheu Thai party and a former justice minister
A common thread is that many of those on the list have either been charged with insulting the monarchy or are known for criticising it, the BBC's Jonathan Head reports from Bangkok. Thailand has draconian laws on lese majeste.
At the scene: Jonathan Head, BBC News, Bangkok
Much about this coup has been textbook predictable; the curfew and censorship, the stiff military pronouncements and martial music on our TV channels. And then there is the unexpected; nervous and well-armed soldiers, surrounding a city-centre branch of McDonalds.
Inside, to the bewilderment of customers lining up for their lunch, a handful of protesters yelled their opposition to the coup through the glass doors. Outside, the soldiers took up positions. One of their trucks started blaring out patriotic songs to try to drown out the protesters.
More protesters arrived, confronting the troops, who seemed unsure what to do; they were blockading a fast-food restaurant that had several other entrances, and was not actually being targeted by anyone. One young soldier was close to tears, after demonstrators screamed in his face. It was brutally hot too.
This is not like the last coup. There is more anger, more tension. The protests have been small so far - just a few hundred people. But they could grow. And the military is jittery. The potential for more dangerous confrontations is real.
On Friday. army chief Gen Prayuth Chan-ocha met key officials and told them that reform must come before any elections.
Gen Prayuth summoned governors, business leaders and civil servants to the Bangkok Army Club.
Six of Thailand's most senior military officers have now been appointed to run the country, with provincial commanders supervising local government.
Unlike in previous coups, there have been no promises of a quick return to civilian rule, our correspondent says.
Gen Prayuth told the meeting: "I want all civil servants to help organise the country. We must have economic, social and political reforms before elections."
"If the situation is peaceful, we are ready to return power to the people," he added.
Meanwhile, the US has suspended $3.5m (£2.1m) in military aid to Thailand from its overall aid package of $10.5 million (£6.2m) and told the army to restore civilian rule.
Washington also urged tourists to cancel trips and halted non-essential visits by US government officials, following Thursday's coup.
Secretary of State John Kerry said there was "no justification" for the coup but an official said the US would continue joint exercises currently taking place with the Thai military.
Thailand's armed forces have staged at least 12 coups since the end of the absolute monarchy in 1932.
There has been a power struggle since Ms Yingluck's brother, Thaksin Shinawatra, was ousted by the military as PM in 2006.
Mr Thaksin and Ms Yingluck have strong support in rural areas but are opposed by many in the middle class and urban elite.
The latest unrest began last year, when anti-government protesters embarked on a campaign to oust Ms Yingluck. An election was held in February but was disrupted and later annulled by the judiciary.