Hours after declaring martial law on Tuesday (May 20), Army Chief Gen. Prayuth Chan-ocha asked where Thailand's weak elected government was hiding, joked about further restricting the media, and denied he was plotting his second coup.

Gen. Prayuth is now under popular pressure to quickly enable Thailand to hold an election to restore the caretaker government to full power.

Thailand is a non-NATO U.S. treaty ally dangerously split between a majority who want to keep their right to vote for democratically elected governments, while a minority hopes the military will appoint a dictatorial regime of apolitical technocrats.

In a surprise pre-dawn power grab, Gen. Prayuth activated a 100-year-old martial law allowing anyone to be imprisoned without charges for seven days, or confined for a "determined period" in their homes, plus the use of military courts for civilian criminal trials, a ban on meetings, and a halt to any transportation by land, water and air.

The Martial Law of 1914 also allows the military to seize or destroy "any place" and "to burn any house or thing which may be useful to the enemy".

Telephones, computers, and other "communication devices," including printed material, can be searched and taken.

Section 10 allows the military "to force labor for supporting military service," including "any person" or "beast of burden".

Gen. Prayuth, who played a role in a 2006 coup against the current government's allies, said his declaration of martial law was not a coup, and he would invoke only the regulations needed to "preserve law and order."

Many Thais and foreigners defied martial law censorship and went to Twitter and Facebook to express skepticism about Gen. Prayuth's action, with some describing it as a "de facto coup".

The decree came after six months of anti-government protests in Bangkok left more than 27 people dead in street clashes, grenade attacks, shootings and stabbings.

Hours after his announcement, Gen. Prayuth held a news conference and was asked why he did not notify the government before declaring martial law.

"Where is the government?" he replied.

Acting Prime Minister Niwattumrong Boonsongpaisan was conspicuously absent throughout Tuesday (May 20) while reportedly meeting his political colleagues at an undisclosed location.

A tellingly weak statement, attributed to Mr. Niwattumrong, advised the military that "any actions need to follow a peaceful path, without violence, discrimination and with equality based on the rule of law."

During Gen. Prayuth's news conference, when a journalist asked a curfew would be imposed to curb Bangkok's political violence, the general jokingly responded:  "How about a curfew for the press?"

His martial law decrees banned at least 10 private and satellite TV and radio stations which mostly churned out strident propaganda for and against the government.

Those broadcasts were extremely popular, with many Thais entranced by the political rhetoric, vulgar accusations, outright distortions, and one-sided updates which were often believed without question.

All media -- including online sites -- were ordered not to "incite unrest" or publish interviews or opinions which could create confusion, according to a Martial Law Order Number Nine update.

"We understand the Royal Thai Army announced that this martial law declaration is not a coup," said U.S. State Department spokesperson Jen Psaki.

"We expect the Army to honor its commitment to make this a temporary action to prevent violence, and to not undermine democratic institutions," she said, and reminded Gen. Prayuth about "the need for elections."

Up until his martial law announcement, Gen. Prayuth tried to portray himself as a neutral counterweight to the confrontations in Bangkok's streets, where anti-government protesters have staged blockades and occupied government buildings since November.

But his opponents point to Gen. Prayuth's role during 2010 when the U.S.-trained military crushed a nine-week-long, pro-election insurrection, resulting in more than 90 deaths -- mostly pro-democracy civilians and some soldiers.

That pro-election movement, known as the Red Shirts, are currently massed on Bangkok's outskirts, threatening to take action if the government is toppled.

After martial law was declared, troops flanked the tens of thousands of Reds at their site on Tuesday (May 20), but the situation remained calm during the day.

In downtown Bangkok, a smaller group of anti-government protesters, led by Suthep Thaugsuban, sheltered behind their street barricades and refused to leave.

Mr. Suthep hopes a sympathetic military will force the removal of the prime minister and appoint an ally to lead Thailand.

This Southeast Asian, Buddhist-majority nation has suffered 18 coups and attempted putsches since becoming a constitutional monarchy in 1932.

Acting Prime Minister Niwatthamrong was named premier on May 9, promoted from his post as commerce minister when Yingluck Shinawatra was ousted as prime minister by the Constitutional Court for nepotism during her 1,000 days in power.

Mrs. Yingluck's wealthy brother, former prime minister Thaksin Shinawatra, lost power in the 2006 coup.

Before allowing fresh polls, the military orchestrated a 2007 constitution and helped boost the Constitutional Court in an apparent bid to maintain the military's influence over elected politicians.

The military also enabled the Senate to change from being fully elected to become its current half-appointed body, to check the elected House of Representatives.

Mr. Thaksin and his allies, however, won elections in 2001, 2005, 2006, 2007, 2011 and 2013.

Mr. Thaksin currently lives in self-exile abroad, avoiding a two-year prison sentence for corruption.

Unable to win at the polls, Mr. Suthep and his allies organized blockades against February's nationwide election which Mrs. Yingluck was easily winning before it was annulled by the same Constitutional Court.

Mr. Suthep is currently dodging an arrest warrant for alleged multiple murders linked to his role alongside the military in 2010 when they crushed the nine-week pro-election protest.

He is also avoiding an arrest warrant for leading the past six months of "insurrection," punishable by life imprisonment or lethal injection.

"Suthep seeks dictatorship," the Bangkok Post warned in a recent editorial.