By Robert Birsel
BANGKOK (Reuters) - Thailand's army chief, General Prayuth Chan-ocha, will begin to govern a polarized country on Friday, a day after he seized power in a bloodless coup in a bid to end six months of turmoil.
Prayuth launched his coup after factions refused to give ground in a struggle for power between the royalist establishment and a populist politician that has raised fears of serious violence and damage to Thailand's economy, southeast Asia's second biggest.
Soldiers detained some politicians from both sides when Prayuth announced the coup after talks he was presiding over broke down. The military censored the media, dispersed protesters and imposed a 10 p.m. to 5 a.m. curfew.
Later, the military summoned ousted Prime Minister Yingluck Shinawatra and 22 associates including powerful relatives and ministers in her government, to a meeting at an army facility at 10 a.m. (0300 GMT) on Friday.
Yingluck is the sister of Thaksin Shinawatra, a billionaire telecommunications tycoon turned prime minister who won huge support among the poor but the loathing of the royalist establishment, largely over accusations of corruption and nepotism.
Yingluck was forced to step down as prime minister by a court two weeks ago, but her caretaker government, buffeted by six months of protests, remained nominally in power, even after the army declared martial law on Tuesday.
The meeting with Yingluck could set the tone for Prayuth's rule as he tries to steer the country out of crisis and fend off international criticism of the latest lurch into military rule.
U.S. Secretary of State John Kerry said there was no justification for the coup, which would have "negative implications" for ties, especially military ones.
"The path forward for Thailand must include early elections that reflect the will of the people," Kerry said in a statement.
He also called for the release of detained politicians.
There was also condemnation from France, the European Union and the United Nations human rights office. Japan said the coup was regrettable and Australia said it was "gravely concerned."
Prayuth is a member of the royalist establishment who has tried for months to keep the army out of the political strife and to appear even-handed. He had good relations with Yingluck when she was prime minister, but he is regarded warily by some Thaksin supporters.
The army chief, who is 60, took over the powers of prime minister but it is not clear if he intends to stay in the position.
The anti-Thaksin protesters want electoral reforms that would end his success at the ballot box. Thaksin or his parties have won every election since 2001.
They royalists have also been demanding a "neutral" interim prime minister to oversee reforms before any new vote.
Many royalist supporters welcomed the coup against a government they had been trying to force out through protests.
Thaksin's "red shirt" supporters were dismayed and angry but said there were no immediate plans for protests that they had vowed in response to a coup.
Protests would be a major test for Prayuth, who commands an army known to contain some Thaksin sympathizers.
In 2010, more than 90 people, most of them Thaksin supporters, were killed in clashes, most when the army broke up protests against a pro-establishment government.
Weary investors have generally taken Thailand's upheavals in stride, and analysts said the impact of the coup on markets might not be too severe.
Thailand's SET index closed before the coup announcement on Thursday, ending 0.2 percent higher. The baht currency weakened to 32.54 per dollar after the coup announcement, from 32.38 earlier.
Thai gross domestic product contracted 2.1 percent in the first quarter of 2014 from the previous three months, largely because of the unrest, which has frightened off tourists and dented confidence, adding to fears of recession.
(Additional reporting by Bangkok bureau; Editing by Steve Orlofsky)