Tens of thousands of Tunisians demonstrated Friday to mourn the death of secularist opposition politician Chokri Belaid and demand the removal of the US-backed Islamist government.

A one-day general strike called by the Tunisian General Labour Union (UGTT) shut factories, banks, offices, schools and shops in the capital and other cities, and state-owned Tunis Air cancelled all of its flights. Bus service continued to run, however.

It was the first general strike in Tunisia in 35 years.

Belaid, 48, a leading member of the left-liberal Democratic Patriots’ Movement, one of 12 parties that make up the Popular Front coalition, was shot and killed Wednesday as he left his home in the Jebel al-Jaloud district of Tunis and headed for work. He was gunned down by an assassin who fled on a motorcycle.

While no one has taken credit for the killing, Belaid’s widow accused the Ennahda party government of colluding with far-right Salafists to murder her husband. Belaid had sharply criticized Ennahda, an offspring of the Muslim Brotherhood, for allowing Salafists to attack cinemas, theaters, bars and secularist groups in recent months. He had made known that he was the target of repeated death threats and had requested police protection.

Over 50,000 people gathered near Belaid’s home on Friday and marched to the Jallaz cemetery, where he was buried. They shouted antigovernment and revolutionary slogans such as “The people want a new revolution,” and “The people want the downfall of the regime.”

Mourners also demanded “Bread, freedom and social justice,” one of the main slogans of the 2011 revolution. At the funeral, demonstrators called Rachid Ghannouchi, leader of Ennahda, “a butcher and a murderer.”

Ominously, an Ennahda official appearing on Al Jazeera television blamed the violence on “foreign hands” and said, “There are foreign intelligence apparatuses operating in Tunisia.”

Two security helicopters hovered overhead and the regime mobilized the army, rather than the hated security police, to contain the huge march. However, police fired tear gas at protesters on the fringe of the march outside the cemetery, as well as at demonstrators who marched to the Interior Ministry. A ministry spokesperson said the police arrested 150 demonstrators in Tunis.

Police fired tear gas to disperse antigovernment protesters in the southern town of Gafsa, a center of the county’s critical potash mining industry and a stronghold of support for Belaid. In Sousse, protesters demanded the resignation of the provincial governor.

Some 10,000 marched in Sidi Bouzid, the southern town known as the birthplace of the Tunisian revolution. It was there in December of 2010 that Mohamed Bouazizi set fire to himself in protest over the confiscation by police of his vegetable cart. Bouazizi’s death sparked an explosion of mass protests and strikes that could not be contained by the pro-regime UGTT and led to the flight of US–backed dictator Zine al-Abidine Ben Ali the following month.

Just weeks later, revolution broke out in Egypt, leading to the downfall of US- and Israeli-backed dictator Hosni Mubarak. The current eruption in Tunisia, the most widespread since the events of late 2010 and early 2011, occurs just days before the second anniversary of Mubarak’s fall.

Belaid’s murder stunned the country and became the trigger for an explosion of pent-up social anger that had been building since shortly after Ennahda came to power, having polled a plurality of votes in October 2011 elections for a constituent assembly. The source of the anger was not only the government’s use of police repression and Salafist violence against its opponents. More fundamentally, it stemmed from the lack of any relief from the mass unemployment and grinding poverty that had sparked the working-class uprising that toppled Ben Ali just over two years ago.

The Islamist regime in Tunisia, like the Muslim Brotherhood Mursi regime in Egypt, is a bourgeois regime supported by Washington. The Ennahda government backed the US-NATO war for regime-change in Libya. It is currently negotiating the terms of a standby loan with the International Monetary Fund, which will include austerity measures directed against Tunisian workers.

Within hours of news of Belaid’s assassination on Wednesday, barricades went up in Tunis and crowds attacked Ennahda offices in at least 12 cities. On Thursday, Prime Minister Hamadi Jebali, secretary general of Ennahda, announced on nationwide television that he planned to dissolve his government and replace it with an unelected government of technocrats to rule until parliamentary elections, scheduled for June.

The announcement, intended to calm popular outrage, only fuelled it. Hundreds of youth stormed a police station in the center of Tunis, throwing furniture, files and equipment into the street. The police responded by firing tear gas.

In Gafsa, hundreds of stone-throwing demonstrators confronted riot police firing tear gas. The army was deployed to contain mass protests in Sidi Bouzid.

The crisis of the Tunisian regime was compounded late Thursday when Prime Minister Jebali’s call for a “nonpartisan” and technocratic government was repudiated by his own party. The Ennahda party issued a statement declaring that Tunisia needed a “political government” based on the results of the October 2011 elections.

The same day, four opposition groupings, Belaid’s own Popular Front bloc, the Call for Tunisia party (Nidaa Tounes), the Al Massar party and the Republican Party, announced that they were pulling out of the national constituent assembly and called for a general strike. The UGTT, fearing the mass protests might escalate into a new revolutionary upheaval, announced a one-day general strike for Friday in an attempt to contain the movement.

The Popular Front bloc is led by the Maoist Workers Party, headed by Hamma Hammami. Hammami and his party have long functioned to head off any independent political movement of the working class and keep Tunisian workers tied to liberal and secularist factions of the bourgeoisie. They are playing the same role in the current crisis.

One of the four bourgeois opposition parties to which the Popular Front is allied, Nidaa Tounes (Call for Tunisia), is led by Béji Caid Essebsi, 86, a long-serving official under the dictatorial regimes of Habib Bourguiba and Ben Ali.

On Friday, Prime Minister Jebali repeated his call for a new government in a somewhat altered form. He said he would not require the approval of the constituent assembly and was confident he would have the support of his party because he was not dissolving his government, but merely replacing all of its members. However, he indicated that if his plan were blocked, he would step down as prime minister.