BANGKOK -- Leading members of Thailand's largest political party surrendered to the military Friday, a day after the head of the army overthrew the country's elected government.
Former Prime Minister Yingluck Shinawatra and her close associates were among about 150 people who had been summoned by the military. Ms. Yingluck arrived at a military facility around noon.
But there were also early signs of defiance toward the military takeover, Thailand's second coup in a decade. Small groups of people opposed to the coup gathered around Bangkok and the northern city of Chiang Mai, displaying signs critical of the military. Some symbolically taped their mouths shut.
Several hundred people gathered in Bangkok's main shopping district and confronted a line of heavily armed soldiers. "Get out, dictators!" the crowd chanted. The protest was organized through Facebook.
"The anti-coup protests have begun," one man shouted.
As the political crisis continued to unfold Friday, the United States announced that it was suspending $3.5 million in military aid to Thailand, according to The Associated Press. State Department spokeswoman Marie Harf said officials were still reviewing whether to cut off an additional $7 million in direct assistance to the country, The AP reported.
The dissent over the military takeover in Thailand underlined what appeared to differentiate the events from those of the previous coup, in 2006, when opposition to the military coalesced more slowly.
One prominent member of the movement supporting the deposed government, Sombat Boonngamanong, wrote on Facebook that he would defy a military summons. "Catch me if you can," he titled his post. "I don't accept the power of the coup makers," he wrote, urging Thais to "join the resistance."
Thai history is strewn with military interventions, but analysts said this was among the most contentious and risky. The governing party, founded by Ms. Yingluck's brother Thaksin Shinawatra, is well organized and has vowed to fight for electoral democracy.
Yet as with the coup in 2006, there were many Thais who said they were grateful toward the military. They blamed politicians for six months of deadlock that led to the coup. "It's time to clean this country up," read a comment by someone who identified himself as Chaiwat Kongpradit. "Hooray! Our hearts are with the Thai military."
The comment was posted on a Facebook page established by the junta, which soon featured a wide range of opinions.
Another comment described the coup as futile because the governing party would most likely win elections again once democracy returns to the country. Mr. Thaksin's political movement has won every election since 2001, but its leaders have been removed from power five times, including three times by the courts.
The junta announced severe restrictions on the media in the hours after Thursday's coup, barring dissemination of "secret" information or anything that could lead to "confusion, provocation, agitation or create conflict or division."
There was a sense among analysts and commentators that Thailand's political turmoil was far from over.
The Bangkok Post, an English-language daily, warned that a coup was "not the solution." The military's takeover was "likely to stir up stiff resistance, provoke acts of violence and possibly cause more loss of life," the paper said in an editorial.
Kong Rithdee, a writer and columnist, said in an email that the coup risked deflating what he called the myth of Thailand as the land of smiles. "The mess that has been in the news presents such a contrast to the fantasy that a lot of people have about Thailand -- and that we have about ourselves, too, to an extent," he said.
A number of travel warnings by foreign governments went beyond routine precautionary advice. The Singapore government warned its citizens that they "should seriously reconsider visiting Thailand at the moment." The warning said, "The situation is unpredictable and volatile, and may evolve quite rapidly."