In one of the largest opposition protests to date, tens of thousands of Tunisians marched on the seat of the elected assembly late on Saturday demanding the government resign.
The protesters were marking 40 days since the assassination of opposition politician Mohammad Brahmi, shot dead outside his home on July 25. His killing has plunged the country into a political crisis.
Demonstrators carrying portraits of Brahmi chanted slogans paying tribute to him and denouncing the government, according to AFP news agency.
Many opposition supporters blame the government for having failed to crack down on Islamist extremists in the wake of Belaid's killing.
Meanwhile, the authorities have blamed Brahmi's killing, and the murder in February of another opposition figure, Chokri Belaid, on Salafist militants.
The opposition is demanding the Islamist-led government resign for what they say is its failure to ensure security or manage the economy in Tunisia, the birthplace of the Arab Spring.
(With AP and AFP)