A Tunisian judge on Thursday ordered the imprisonment of Rached Ghannouchi, leader of the opposition party Ennahda and one of President Kais Saied's most vocal critics.
Mr Ghannouchi, a former parliamentary speaker, is at least the 20th person to be held in a recent crackdown on critics of Mr Saied.
He was arrested on Monday by counterterrorism prosecutors for allegedly making "inflammatory comments".
The judge's decision to send him to jail until his trial came after an eight-hour investigation, his lawyer, Monia Bouali, said.
"It was a ready decision to imprison Ghannouchi only because of Ghannouchi's expression of his opinion," Ms Bouali told Reuters.
Three other prominent Ennahda officials — Mohamed Goumani, Belkacem Hassan and Mohammed Chnaiba — were also arrested, Ms Bouali said.
"I am optimistic about the future," Mr Ghannouchi, 81, said on Facebook after the decision.
Mr Ghannouchi, whose party has roots in political Islam, lived in exile in the 1990s and returned during Tunisia's 2011 uprising that brought democracy. He was speaker in the parliament suspended by Mr Saied in July 2021.
Mr Saied dismissed the government at the same time and dissolved parliament last year before introducing a new constitution that increased the president's powers, moves that his opponents say amounted to a coup.
Mr Ghannouchi told an opposition meeting on Saturday that: “Tunisia without Ennahda, without political Islam, without the left, or any other component, is a project for civil war."
He said those who “celebrated the coup are extremists and terrorists”.
Ennahda described Mr Ghannouchi's arrest as a “dangerous development".
Tunisian authorities on Tuesday banned meetings at all Ennahda offices. Police raided the party headquarters and emptied the building to start a search that continued for days, Ennahda officials told Reuters.
Mr Ghannouchi has faced repeated judicial questioning over the past year on charges relating to Ennahda's finances and to allegations that the party helped Islamist extremists travel to Syria to fight, accusations Mr Ghannouchi and the party deny.
The United States said Mr Ghannouchi's arrest was a "troubling escalation".
"The Tunisian government’s obligation to respect freedom of expression and other human rights is larger than any individual or political party, and is essential to a vibrant democracy and to the US-Tunisia relationship," said Vedant Patel, Deputy Spokesperson for the US State Department.