Tunisia's Islamist opposition leader and speaker of the dissolved parliament Rached Ghannouchi appeared at a Tunis police station on Monday to answer questions over what his party has said are accusations relating to terrorism.
Dozens of protesters including lawyers and political activists gathered outside the police station to demonstrate against the questioning of Ghannouchi, who has denounced President Kais Saied's seizure of broad powers.
"The police state is finished. We are with you Ghannouchi," some of them chanted. Others chanted: "Freedom".
Officials in Ghannouchi's Ennahda party said on Saturday that Ghannouchi and another member, former prime minister Ali Larayedh, would be questioned by police for "sending jihadists to Syria", but without giving details.
Tunisian authorities have not given any statement on the reason for Ghannouchi's summons. Last month several former security officials and two Ennahda members were arrested on charges connected to Tunisians travelling for jihad.
The Ennahda leader has been a key player in Tunisian politics since the 2011 revolution that brought democracy, with his party joining several successive coalition governments.
When Saied seized most powers last summer and shut down the parliament, Ghannouchi accused him of an anti-democratic coup, something the president has denied.
Speaking to Reuters late on Saturday, Ghannouchi said the summons was "a new attempt to target opponents and a new step towards exclusion".
Larayedh said he had not been told officially why he was being summoned but that news had leaked that it was connected to the sending of jihadists to Syria.
Security and official sources estimated that around 6,000 Tunisians travelled to Syria and Iraq last decade to join jihadist groups including Islamic State. Many were killed there while others escaped and returned to Tunisia.
"I was against this phenomenon and took measures to limit it," Larayedh said, saying the summons had been concocted to distract public attention from high prices.
Secular parties have accused Ennahda of being lenient towards Islamist militants, something the party has long denied.
(Reporting by Tarek Amara; Writing by Angus McDowall; Editing by Mark Potter)