A Turkish court on Tuesday ordered that six human rights activists including Amnesty International's Turkey director remain in custody for aiding a terror group, in a case the rights watchdog called a "travesty of justice."

Amnesty's Turkey director Idil Eser was detained on July 5 with seven activists and two foreign trainers during a digital security and information management workshop in an island south of Istanbul.

"Six were remanded in custody and four released on judicial control," Amnesty International's Turkey researcher Andrew Gardner told AFP.

Prosecutors accuse them of "committing a crime in the name of a terror organisation without being a member," he said.

Their detention sparked international alarm and amplified fears of declining freedom of expression under President Recep Tayyip Erdogan.

The ruling came a day after the activists, who have not yet been put on trial or formally charged, gave statements to prosecutors for the first time since their detention.

Eight of those detained were Turkish rights activists, including Ilknur Ustun of the Women's Coalition and Veli Acu of the Human Rights Agenda Association. Four of those have now been released, Gardner said.

Two foreigners -- a German and a Swede who were leading the digital information workshop -- remain in pre-trial detention.

Gardner said the court verdict was a "shocking travesty of justice."

"It is politically motivated targeting not just of these six human rights defenders who have been remanded in pre-trial prison custody but it is taking aim at Turkey's entire human rights movement," he told AFP.

"What we've learnt today is that defending human rights has become a crime in Turkey," Gardner said.

"After this decision none of us who defend human rights in Turkey, whether it is Amnesty International or other organisations, are safe in this country. This decision cannot be allowed to stand."

Sweden's foreign ministry was "concerned by the detention of a Swedish national," a spokesman told AFP, adding: "We are looking into the accusations."

Germany's Social Democrat chief Martin Schulz hit back at German Chancellor Angela Merkel for her silence, telling weekly Der Spiegel Erdogan was "dissolving democracy".

"When Erdogan throws more journalists and human rights defenders in prison, it is no longer possible to be silent," he said.

- Massive crackdown -

The Turkish leader said this month the activists were detained on a tip-off they were working against the government, comparing them to those involved in a failed putsch in July last year.

Gardner earlier said the meeting had been a "routine" workshop and there was nothing suspicious about it.

"What is absolutely crystal clear, one hundred percent clear is this was a routine human rights workshop -- the sort of workshop that happens all over Turkey, in fact the sort of workshop that happens all over the world," he said.

Amnesty's secretary-general Salil Shetty said the investigation was not "legitimate", branding it "a politically motivated witch-hunt that charts a frightening future for rights in Turkey."

Turkish authorities have launched a massive crackdown on people suspected of links to a movement led by US-based Muslim preacher Fethullah Gulen, who denies Ankara's accusations of masterminding the attempted power grab.

Amnesty International's Turkey chair Taner Kilic was also arrested last month, accused of links to Gulen.

More than 50,000 people have been jailed and over 100,000 including judges, teachers, police and other state servants have been dismissed.

Gardner said before the court ruling that country director Eser remained "in good spirits."

"She sent messages that as soon as she is released she wants to carry on from where she left off," he said.

Source: AFP