Manama: A Bahraini rights activist was formally charged on Thursday with insulting the ministries of defence and interior.

Nabeel Rajab, who heads the Bahrain Centre for Human Rights, was detained on October 1 over his tweets alleging that Bahrain’s security institutions were incubators for extremist ideology. His lawyer, Jalila Al Sayed, said Rajab was also accused of “intimidating” security forces.

A court date was set for October 19. Al Sayed said the charges carry a possible prison sentence of up to three years. Rajab insists he was practicing his right to free speech.

State prosecutors also ordered Rajab held another week starting Thursday. A statement by the prosecutor’s office carried by the official Bahrain News Agency said, without identifying Rajab by name, that the person who had posted “insults” on his personal social media account is being charged for “defamatory allegations” against both security ministries.

Rajab wrote on Twitter on September 28 that security institutions are “the first ideological incubator” for Bahrainis who joined Daesh fighting in Iraq and Syria.

A video recently released purportedly shows four Bahrainis who joined Daesh calling on other Bahrainis to take up arms against the island country’s monarchy and Shiite community. They also call for a Sunni boycott of upcoming November 22 parliamentary elections.

One of the militants in the video is an officer who defected from Bahrain’s Interior Ministry, according to the SITE Intelligence Group, which monitors terrorist groups.

Bahrain has clamped down on activists since protests erupted in 2011. Rajab previously served two years in prison for leading anti-government protests. He was released in May.