Khalil al-Marzouk was detained in mid-September by police investigating what authorities called his promotion of terrorism.

The deputy leader of Bahrain’s largest opposition party is to face trial on charges including inciting terrorism, the public prosecutor of the Gulf Arab kingdom said on Saturday.

Khalil al-Marzouk was detained in mid-September by police investigating what authorities called his promotion of terrorism, angering his Al Wefaq party, an Islamist group which says it advocates non-violent methods of activism.

In a statement published by the state news agency, First Attorney General Abdulrahman Al Sayed said the Public Prosecution had completed its investigations of charges against Marzouk and ordered him to be jailed pending criminal trial.

Charges included “inciting terrorism and promoting acts which constitute crimes of terrorism, as well as using his position and management of a legally formed political association to call for the commitment of crimes which constitute terrorist acts”.

The statement said Marzouk had been interrogated in the presence of a lawyer and was confronted with recordings of speeches he made during which he adopted the principles shared “by the terrorists who have committed many acts of planting explosives, murder and all forms of violence.”

He was also accused of supporting an opposition group called the February 14 Coalition, a network of activists that uses social media to organise anti-government protests.

The group has been described by the prosecution as a terrorist organisation.

Bahrain, base for the U.S. Navy’s Fifth Fleet, has been in political turmoil since protests erupted in 2011 led by majority Shi’ite Muslims demanding full powers for parliament and an end to the Sunni monarchy’s political domination.

Shi’ites have long complained of entrenched discrimination in areas such as employment and public services, despite the denials of the Sunni-led government.

Al Wefaq demands a constitutional monarchy with a government chosen from within a democratically-elected parliament.

The party reacted to Marzooq’s detention last month by saying it appeared designed to suppress dissent and “wipe out” opposition political action.

A hearing for the case is scheduled for October 24.