The activists, who include the local head of Amnesty International and a German and a Swede, face up to 15 years in prison on charges that include membership in and aid to an ?armed terrorist organization?

ISTANBUL: Eleven human rights activists accused of terrorism charges were set to go on trial in Turkey on Wednesday in a case that has sparked widespread concern in the West and become a flashpoint in Ankara?s tension with Europe.

The activists, who include the local head of Amnesty International and a German and a Swede, face up to 15 years in prison on charges that include membership in and aid to an ?armed terrorist organization?.

The activists were detained in July after they participated in a workshop on digital security held on an island near Istanbul. The case has deepened concerns that Turkey is sliding faster towards authoritarianism under President Tayyip Erdogan.

Since a failed coup last year, authorities have jailed pending trial more than 50,000 and sacked or suspended some 150,000. Western allies fear Erdogan is using the coup as a pretext to root out opponents and quash dissent.

The first hearing was due to begin at 10 am (0700 GMT). Among those arrested were Amnesty International?s Turkey director, Idil Eser, German citizen Peter Frank Steudtner and Swedish citizen Ali Gharavi.