Raiding homes early on March 3, Turkish police detained 10 people, most of them journalists, drawing condemnation from the EU and international media watchdogs.

The arrests “in the absence of clear reasonable cause, will have a chilling effect on free speech,” Emma Sinclair-Webb, a researcher for the group, said in a statement.

It was the latest episode in a long-running probe into Ergenekon, a purported secularist network that allegedly plotted assassinations and bombings to destabilize the AK Party and prompt a military coup.

Critics charge the investigation, afoot since 2007, has degenerated into a campaign to bully critical media and the opposition.

“The government should take steps to remove all restrictions in law on freedom of expression and to demonstrate a commitment to press freedom and lively critical debate, which together are the hallmarks of a democracy,” Sinclair-Webb said.

Turkish Prime Minister Recep Tayyip Erdogan has rejected any responsibility, voicing hope the judiciary would “complete the process speedily.”

Among those detained was Nedim Sener, a prominent journalist who last year received the International Press Institute’s “World Press Freedom Hero” award for a book that put blame on the security forces for the 2007 murder of ethnic Armenian journalist Hrant Dink. Newspapers expressed shock also over the detention of Ahmet Sik, credited with being among the first to report that some generals had plotted to oust the AKP, months before the Ergenekon probe had even began.

All the detained journalists are known critics either of the investigation or the police, as were three colleagues from an opposition website who were arrested last month.