Tunisia's ruling Islamist Ennahda party has rejected Prime Minister Hamdi Jebali's proposal to dissolve the government and install a cabinet of technocrats.
Mr Jebali’s move came as a bid to restore calm after the killing of opposition leader Chokri Belaid.
Unrest has erupted over the killing, deepening the worst crisis since the country's 2011 revolution.
Protesters have set the local headquarters of the main Islamist Ennahda party on fire and a police station in the provincial town of Kelibia.
Police fired teargas to scatter protesters near the interior ministry in Tunis and stone-throwing youths in the southern mining town of Gafsa.
At least seven people were said to be injured in the violence.
Crowds ransacked electronics shops in Sfax.
Further disturbances loom tomorrow when labour unions plan a general strike in protest at the assassination of Mr Belaid.
His funeral is also expected to be held tomorrow.
An aide to Hussein Abassi, leader of the UGTT union, Tunisia's biggest, said he had received a death threat after announcing the country's first general strike in 34 years.
Wary of further violence, many shops in Tunis closed early today.
France, the old colonial power in Tunisia, has said it would shut its schools in Tunis for the next two days.
The prime minister announced late last night that he would dismiss the government led by his moderate Islamist party in favour of a non-partisan cabinet until elections could be held soon.
But the idea met swift resistance.
A senior Ennahda official said Mr Jebali had not sought approval from his party, suggesting the Islamist group was split over the move to supplant the governing coalition.
"The prime minister did not ask the opinion of his party," said Abdelhamid Jelassi, Ennahda's vice-president.
"We in Ennahda believe Tunisia needs a political government now. We will continue discussions with other parties about forming a coalition government."
Ennahda's two secular coalition partners as well as the main opposition parties also rejected any move to a government of technocrats, demanding as well that they be consulted before any new cabinet is formed.