BANGKOK -- Thailand's powerful military chief intervened for the first time in the country's latest political crisis, declaring martial law and dispatching gun-mounted jeeps into the heart of the capital with a vow to resolve the deepening conflict as quickly as possible.
The military insisted it was not seizing power, and it left the nation's severely weakened caretaker government intact. But a series of official edicts announced throughout the day which steadily expanded the military's power and included media censorship and threats to prosecute opponents fueled speculation the troops had carried out what Human Rights Watch described as "a defacto coup."
Despite Tuesday's dramatic events, life continued normally in most of the country, with residents largely unfazed by the declaration and tourist sites open. But the intervention, which follows six months of crippling protests that killed 28 people and injured more than 800, left the country at another precarious crossroads -- its fate now squarely in the hands of the military.
"The key going forward will be the military's role in politics," said Thitinan Pongsudhirak, director of the Institute of Security and International Studies at Bangkok's Chulalongkorn University. "If they play the role of enforcer of law and order and even mediator ... this could be a resolution to the impasse."
But if they don't, "we can expect protests and turmoil from the losing side."
Thailand, an economic hub for Southeast Asia whose turquoise waters and idyllic beaches are a world tourist destination, has been gripped by off-and-on political turmoil since 2006, when former Prime Minister Thaksin Shinawatra was toppled by a military coup after being accused of corruption, abuse of power and disrespect for Thailand's king. His overthrow triggered a power struggle that in broad terms pits Thaksin's supporters among a rural majority against a conservative establishment in Bangkok.
The army action came a day after Thailand's caretaker prime minister refused to step down, resisting pressure from a group of senators calling for a new interim government with full power to conduct political reforms.
It also followed threats by anti-government protesters to intensify their campaign to oust the ruling party, and an attack last week on protesters that killed three people and injured over 20.
The military, which has staged 11 successful coups since the end of absolute monarchy in 1932, is widely seen as sympathetic to the protest movement. Cabinet ministers said army chief Gen. Prayuth Chan-Ocha did not consult the government before issuing the surprise announcement Tuesday to take charge of security nationwide.
Although soldiers entered multiple television stations to broadcast the army message, life in this vast skyscraper-strewn metropolis of 10 million people and the rest of the country remained largely unaffected, with schools, businesses and tourist sites open and traffic flowing normally.
Near one of Bangkok's most luxurious shopping malls, bystanders stopped to snap smiling "selfies" of themselves with armed soldiers in jeeps and Humvees.
In the military announcement, Prayuth cited a 1914 law giving authority to intervene during crises. He said the military was acting to prevent street clashes between political rivals, and that it would "bring back peace and order to the beloved country of every Thai as soon as possible."
Speaking to reporters later, Prayuth said martial law would last until "there is stability," and that it was needed to force the two sides to talk about a solution.
"Don't worry," he said. "Everything will still go on normally. (We) will try not to violate human rights -- too much."
Acting Prime Minister Niwattumrong Boonsongpaisan called an emergency Cabinet meeting at an undisclosed location. Afterward, he issued a brief statement saying only that the government hopes the military action will "bring peace back to the people of every group and every side."
Education Minister Chaturon Chaisang, however, said in a post on his Facebook page that martial law was not an answer and warned it could "eventually spiral into a situation in which the military has no choice but to stage a coup."
Thailand's problems are "fundamentally political problems that must be solved through political processes under democracy ... not military or security measures," Chaturon said.
The latest round of unrest started in November, when demonstrators took to the streets to try to oust then-Prime Minister Yingluck Shinawatra, Thaksin's sister. She dissolved the lower house of Parliament in December in a bid to ease the crisis, and later led a weakened, caretaker government.
Earlier this month, the Constitutional Court ousted Yingluck and nine Cabinet ministers for abuse of power. But the move, which left the ruling party in charge, did little to resolve the conflict.
The anti-government protesters want an interim, unelected government to implement vaguely defined reforms to fight corruption -- and to remove the Shinawatra family's influence from politics. Critics at home and abroad call the idea unconstitutional and undemocratic.
The army issued edicts throughout the day. In one, they asked TV and radio stations to interrupt programming for army broadcasts. In another, they ordered police "to stop gatherings or activities that oppose" a new military command center established to oversee the imposition of martial law.
The military also asked social media sites to suspend services that could incite violence, and ordered journalists not to disseminate interviews "that could incite wider conflict, distort, cause confusion in the society and lead to violence." Those who do will face prosecution, the army said.
At least 10 politically affiliated private TV stations from both sides ceased broadcasting after armed soldiers entered and requested they do so.
Brad Adams, Asia Director for Human Rights Watch, denounced the army move, calling it "a de facto coup."
"The military has pulled a 100-year-old law off the shelf that makes the civilian administration subordinate to the military, effectively rendering the executive, legislative and judicial branches powerless," Adams said. "The broad powers conferred on the military mean that there are no legal safeguards against rights violations."
In Washington, the Obama administration said the Thai military's declaration of martial law is allowed by the nation's constitution and won't trigger sanctions.
However, U.S. State Department spokeswoman Jen Psaki said the U.S. expected the army "to honor its commitment to make this a temporary action to prevent violence, and to not undermine democratic institutions."
Prayuth said rival protesters could remain at their respective rally sites as long as they remain peaceful and stop marching.
The leader of the pro-government Red Shirt movement, Jatuporn Prompan, said his group could accept martial law, but wouldn't tolerate a coup.
"We will see what the army wants," he said, warning that the undemocratic removal of the country's caretaker government "will never solve the country's crisis and will plunge Thailand deeper into trouble."
Associated Press writers Jocelyn Gecker and video journalists Kiko Rosario and Raul Gallego Abellan in Bangkok and Deb Riechmann in Washington contributed to this report.