Street clashes erupted Monday outside Tunisia's army-barricaded parliament, a day after President Kais Saied ousted the prime minister and suspended the legislature, plunging the young democracy into a constitutional crisis.

Saied sacked Prime Minister Hichem Mechichi and ordered parliament closed for 30 days, a move the biggest political party Ennahdha decried as a "coup", following a day of angry street protests against the government's handling of the Covid pandemic.

Soldiers from early Monday blockaded the assembly in Tunis while, outside, the president's backers hurled stones, bottles and insults at supporters of the Islamist-inspired Ennahdha, whose leader was barred entry to the complex.

Troops also surrounded the office of Mechichi who was yet to officially react to the events rocking the North African country.

Saied's dramatic move -- a decade on from Tunisia's 2011 revolution, often held up as the Arab Spring's sole success story -- comes even though the constitution enshrines a parliamentary democracy.

It "is a coup d'etat against the revolution and against the constitution," Ennahdha, the lead party in Tunisia's fractious ruling coalition, charged in a Facebook post, warning that its members "will defend the revolution".

The crisis follows months of deadlock between the president, the premier and Ennahdha chief Rached Ghannouchi, which has crippled the Covid response as deaths have surged to one of the world's highest per capita rates.

Saied declared on Sunday that he had "taken the necessary decisions to save Tunisia, the state and the Tunisian people," after a day where Covid street protests flared in multiple cities.

The president, who under the constitution controls the armed forces, warned his opponents against taking up arms, threatening that if anyone "fires a single bullet, our forces will respond with a rain of bullets".

Tunisian police also shuttered the local bureau of Qatari-based Al Jazeera television, the network's Tunis director Lotfi Hajji said, warning that "what is happening is very dangerous, it is proof that freedom of the press is threatened".

- 'Imminent danger' The president's power-grab sparked jubilant rallies late Sunday by many thousands of his supporters who flooded the streets of the capital, waving the national flag and sounding their car horns as fireworks lit up the sky.

But the shock move was criticised abroad, with Germany urging a rapid "return to constitutional order".

The foreign ministry in Turkey, where the government supports Ennahdha, said it was "deeply concerned" and called for "democratic legitimacy" to be restored.

Since Saied was elected in 2019, he has been locked in a showdown with Mechichi and Ghannouchi, who is also house speaker. The rivalry has blocked ministerial appointments and diverted resources from tackling Tunisia's many economic and social problems.

In the chaotic scenes outside parliament Monday, Ghannouchi admonished an army officer who was blocking access and who had declared the troops were "the protectors of the nation".

Ghannouchi retorted that "the Tunisian people will never accept an authoritarian government, whatever your efforts".

Saied had declared Sunday that the constitution allowed him to suspend parliament in case of "imminent danger", later clarifying the shutdown would be for 30 days.

Saied said he would assume executive power "with the help" of a government whose new chief he would appoint himself.

The president also lifted parliamentary immunity for lawmakers.

- 'Birth of a dictator' - In the 10 years since Tunisia's popular revolution toppled dictator Zine El Abidine Ben Ali, the small country has had nine governments.

Some of them have lasted only a few months, hindering the reforms needed to revamp its struggling economy and poor public services.

Tunisia has recently been overwhelmed by Covid-19 cases which have raised the death toll to more than 18,000 in a nation of 12 million.

Last week, Mechichi fired his health minister.

Sunday's political drama began with mass protests against the government for its failures in tackling the pandemic.

"The people want the dissolution of parliament," the crowd had chanted outside the legislature, while protests were also reported in Gafsa, Kairouan, Monastir, Sousse and Tozeur.

Several demonstrators were arrested and a journalist was wounded when protesters hurled stones and police fired tear gas canisters.

A senior Ennahdha official, speaking to AFP on condition of anonymity, alleged that the protests before Saied's announcement, and the subsequent celebrations, had all been choreographed by the president.

"We are also capable of organising large demonstrations to show the number of Tunisians who are opposed to these decisions," the official warned.

After Saied's announcement, one jubilant supporter, Nahla, was brandishing a Tunisian flag and hailed the "courageous decisions", adding that "this is the president we love!"

But one man, aged in his forties, watched on without enthusiasm and said: "These fools are celebrating the birth of a new dictator."