A protester holds a placard during a rally outside the court house where the trial of eleven human rights activists is taking place in Istanbul on Wednesday. (Yasin Akgul/AFP via Getty Images)

Salil Shetty is secretary general of Amnesty International.

For more than five decades, Amnesty International has fought for human rights in Turkey. Some of the country’s best-known figures — from poets to presidents — have at one time or another been classified as Amnesty Prisoners of Conscience and benefited from the fruits of our campaigning.

Now, in a painfully ironic twist, my Amnesty colleagues find themselves on trial in Istanbul. Idil Eser and Taner Kilic, the director and chair of Amnesty International Turkey, are in the dock with nine other leading human rights defenders. They have both spent months behind bars after being arrested on absurd terrorism charges. Their trial begins in Istanbul on Wednesday. If convicted they could face jail terms of up to 15 years.

While Kilic was arrested at his home in Izmir, the choreography of the other arrests could have been lifted from a Hollywood movie script. On July 5, Eser and seven other prominent Turkish human rights activists were meeting on a small island near Istanbul for a routine training workshop. Their trainers, one from Germany and another from Sweden, were teaching them about well-being and digital security. Suddenly Turkish security forces stormed in. The 10 activists were driven to a police station, interrogated and ultimately imprisoned.

Earlier this month the authorities charged them with membership in an “armed terrorist organization.” Kilic, who had been detained a month earlier on a separate set of baseless charges, was also included in this indictment on the grounds that he was aware that the workshop was going to take place. He also faces additional charges, the first hearing for which begins Thursday.

The prosecution alleges that the workshop had been a “secret meeting” for the purposes of organizing “an uprising” aimed at fomenting chaos in the country. Nothing could be further from the truth. For a start, it was anything but secret. Indeed one of the participants, Nalan Erkem, had even posted a photo of the hotel on her Instagram account. “Where are you staying?” asked a friend beneath the photo. “At the Ascot Hotel,” Erkem replied.

The prosecution essentially claims that the entirely open and peaceful activities of these human rights defenders amount to “assisting terrorist organizations.” Eser is linked by the prosecutor to three unrelated and opposing organizations characterized by the authorities as involved in terrorism. The case against her includes allegations that Amnesty International sent a letter to the South Korean Embassy in Turkey asking them to end the sale of tear gas canisters to Turkey following the Gezi Park protests against the government in 2013. This is the type of bread-and-butter work a human rights organization such as Amnesty International does, and it’s impossible to see how anything related to it could be construed as “terrorism.” What’s more, this letter was sent before Eser had joined the organization.

Kilic is accused of downloading and using a phone messaging application called Bylock, allegedly the preferred communications channel of the Gulen movement, which the Turkish government accuses of masterminding last year’s failed coup. However, two independent forensic analyses of Kilic ’s phone commissioned by Amnesty International found that there is no evidence that Bylock was ever on his phone.

Ilknur Ustun, a women’s rights activist arrested as part of the group on the island, is accused of requesting funding from “an embassy” to support a project on “gender equality, participation in policy making and reporting.” She wrote about these charges from prison, saying: “If this is a crime … we’ll continue to commit it.” And this brings us to the crux of their arrests.

Sixteen months after the failed coup attempt, the post-coup crackdown shows no sign of abating. The prisons are full, the courthouses overloaded and fear has become the new norm. Tens of thousands have been jailed. Dozens of media organizations have been shut down. Turkey has now become the world’s largest jailer of journalists. More than 100,000 civil servants have been dismissed under state of emergency decrees and many, correspondingly tainted as “terrorists,” are no longer able to continue in their careers. Last week, the renewal of Turkey’s state of emergency for the fifth time passed largely unnoticed. And yet in this febrile atmosphere, a few people are bravely speaking out and trying to stem the rapidly creeping tide of repression.

While the Turkish government has the duty to ensure security, protect its population and prosecute those responsible for violent attacks, individuals should only be detained and investigated where there is sufficient evidence against them. In Turkey, the act of defending human rights is itself becoming a crime. Criminalizing peaceful activism not only affects those whom the Turkish authorities are attempting to silence but also everyone who values the importance of justice and equal society.

Today the eyes of the world will be on the Istanbul central court for what is an acid test for the Turkish justice system. I am grateful to the many people around the world who have raised their voices against this injustice. But we need to do more. We can stay silent no longer while injustices are committed in plain sight. In the words of Turkish writer, Aziz Nesin, a prisoner of conscience in 1964: “We are responsible not only for what we say but what we fail to say by staying silent.”