Thai coup leaders 'must end repression' - Amnesty
Thailand's military government has engaged in "widespread" human rights violations since the May coup, Amnesty International says.
In a report, the rights group cited arbitrary detentions, a clampdown on free speech, allegations of beatings and unfair trials as examples.
It called on the junta to "end this disturbing pattern of repression".
The military took power on 22 May after months of anti-government protests, saying it would return stability.
At least 27 people died during the six-month campaign by protesters to oust elected leader Yingluck Shinawatra.
The junta had described its measures as necessary and proportionate to the need to preserve security, Amnesty said.
But it said: "Security considerations cannot justify the large-scale and multi-dimensional human rights violations that have been perpetrated".
The report said 665 Thais had been ordered to report and/or detained and arrested by the authorities since the coup.
These included politicians, academics, activists and journalists. Some of them were held for up to a week without charge or trial, and could not make contact with lawyers or family.
Amnesty says they were held on "vague and flimsy grounds", such as being given time to "cool off" or for "attitude adjustment".
Amnesty also said it had received credible reports of torture from some detainees, including from political activist Kritsuda Khunasen. She claimed she was beaten and asphyxiated with a plastic bag if she did not answer interrogators' questions satisfactorily.
Amnesty said the junta had blocked more than 200 websites, closed some television and radio stations, and clamped down on peaceful protests. It added that some civilians had been tried in military courts and denied a right to appeal.
"The cumulative effect of these broad restrictions... are engendering a climate of fear and a culture of enforced silence," the rights group said.
In its response to the report, the government said Amnesty had "failed to acknowledge the pressing needs at the time to bring the emergency situation back to normalcy". It said most Thais felt safer since the coup.
On Kritsuda Khunasen, it said an investigation had found no evidence of mistreatment. It also said those who had been told to report in and detained - a number it put at 471, of whom 411 showed up - had been released.
Analysis: Jonathan Head, BBC South East Asia correspondent
The title of the Amnesty report - "Attitude Adjustment" - refers to the Thai military's explanation for its mass detention of opposition figures after the coup, and it tells you a lot about their ambition; to snuff out all open opposition, and to redesign the political system so that Thaksin Shinawatra's seemingly unbeatable vote-winning machine is marginalised - all in a timescale of just a year. Those goals have inevitably pushed human rights aside.
The abuses listed by human rights groups like Amnesty are not on the scale seen after military coups a few decades ago. There have been no large-scale disappearances, killings or torture. But some activists have been secretly detained. A few detainees have reported torture. And any attempt to organise even the slightest show of dissent is being shut down. Many of those arrested are being tried by military courts.
This is not hands-off military rule - it often feels repressive, for all General Prayuth's talk of restoring happiness to the people. The military is in particular going after anyone who may have criticised the monarchy over the past two years, and anyone with suspected links to the shadowy armed groups which loosely support the ousted government. Statements by senior officers suggest it is still nervous about possible resistance to their coup.
Since the coup the military has strengthened its hold. Last month, coup leader General Prayuth Chan-ocha was named interim prime minister by a legislature hand-picked by the junta.
His cabinet was sworn in last week. Though fewer than half its members are from the military, they are in charge of key ministries such as defence, foreign affairs and justice.
The junta is also appointing a reform council to draft a new constitution by July 2015. It says political reform is needed before elections can be held.
Thailand has been embroiled in political turmoil since the military removed Thaksin Shinawatra - brother of ousted leader Yingluck - in a 2006 coup.
Mt Thaksin received huge support from poor rural voters who were aided by his policies, but he was despised by the urban elite, who viewed him as corrupt. The military backs the urban elite.
Parties allied to Mr Thaksin have been elected in all the elections since the 2006 coup, however, because of his strong rural support base, leaving Thailand locked in a cycle of unrest.