Tunisian police detained a politician and a prominent, politically connected businessman on Saturday, their lawyers said, adding that authorities had not given reasons for the arrests.
The arrested men are Khayam Turki, a former finance minister, and Kamel Ltaif, a construction magnate with close ties to successive coalition governments.
A spokesperson for the Interior Ministry did not immediately respond to a request for comment.
Ennahda, the biggest in the opposition, said the arrest of Turki was aimed at intimidating President Kais Saied's opponents.
The Salvation Front, the main opposition coalition against Saied, condemned his arrest, saying police had questioned him several times for meeting opposition figures at his home.
Rights groups have voiced increasing concern over political freedoms in Tunisia since Saied's seizure of most powers in 2021 and his moves to assume ultimate authority over the judiciary.
Neither Turki nor Ltaif have been prominent critics of the president.
Saied's political opponents, whom he has labelled traitors, have accused him of a coup aimed at unpicking the democracy built after the 2011 revolution.
Saied has denied that, saying his moves were lawful and needed to save Tunisia from chaos. He has promised to uphold rights and freedoms won in the revolution.
Over recent months authorities have arrested or opened investigations into several of Saied's political opponents.
Turki, a former leading figure in Ettakatol party, was at one stage proposed by a coalition of parties as a candidate for prime minister. Police raided his house to arrest him at dawn, his lawyer Abdel Aziz Sid said by phone.
The local Mosaique FM radio station said Turki's arrest was on suspicion of plotting against state security, without citing a source.
The businessman, Ltaif, was also arrested at his home, his lawyer Redha Bel Hadj said by phone. Tunisian analysts describe him as an influential figure since the revolution.
