TUNIS: The assassination of a prominent leftist opposition leader in Tunisia unleashed protests Wednesday across an already-tense nation teetering on the edge of a political crisis.

The rallies saw armored vehicles patrolling the tear-gas-choked streets of the capital and prompting the country’s prime minister to announce the formation of a government of technocrats.

The killing of Chokri Belaid was a chilling escalation of ongoing political violence in Tunisia and brought immediate accusations of government negligence, if not outright complicity – allegations that the ruling party denied.

“I have decided to form a government of competent nationals without political affiliation, which will have a mandate limited to managing the affairs of the country until elections are held in the shortest possible time,” PM Hamadi Jebali said in a televised address to the nation.

Jebali said that plans to form a government of technocrats had stalled before the “odious [killing] that has shocked our people.”

“[Belaid’s] assassination has quickened my decision, for which I assume full responsibility before God and before our people,” he added.

He did not name future ministers nor set a date for the cabinet reshuffle, which must be confirmed by the national assembly.

It was the first assassination of a political leader in post-revolutionary Tunisia. Belaid, a 48-year-old lawyer, was known for his virulent criticism of the Islamist-dominated government and his denunciations of the political violence. He was shot four times at point-blank range outside his home.

His death shook an already tense political scene. The ruling coalition, led by the moderate Islamist Ennahda Party, has been in stalled negotiations with opposition parties to expand the coalition and redistribute ministerial portfolios in an effort to calm the country’s fractious politics.

With its relatively small, largely educated population of 10 million, Tunisia has been widely expected to have the best chance of successfully transitioning to democracy since dictator Zine al-Abidine Ben Ali’s ouster in January 2011. Its first post-dictatorship election brought Ennahda’s moderate Islamists to power in coalition with two secular parties. But ultraconservative Muslims known as Salafists have also been on the rise, and have often resorted to violence in their push for strict Islamic law.

The swift and shocked international reaction to the assassination underlined the global significance Tunisia’s politics have for the rest of the world.

“There is no justification for an outrageous and cowardly act of violence like this,” U.S. State Department spokeswoman Victoria Nuland said.

“There’s no place in the new Tunisia for violence. We urge the government of Tunisia to conduct a fair, transparent and professional investigation to ensure the perpetrators are brought to justice, consistent with Tunisian and international law.”

French President Francois Hollande also expressed his concern. “This murder deprives Tunisia of one of its most courageous and free voices,” he said in a statement.

The scenes in Tunis Wednesday were reminiscent of the final days of Ben Ali as protesters surged down the tree-lined Bourguiba Avenue toward the Interior Ministry chanting “the people want the fall of the regime” and were met with volleys of tear gas and riot police. A Tunisian policeman was killed in the clashes between the security forces and protesters, the Interior Ministry said.

“Policeman Lotfi Alzaar, 46, died Wednesday afternoon ... after sustaining a chest injury caused by rocks thrown during an operation to disperse a group of protesters in Bab al-Jazira” in central Tunis, the ministry said.

Protests flared across the rest of the country as well, with fierce clashes in the southern town of Gafsa and the coastal cities of Sousse and Monastir. Ennahda offices were also attacked in several towns, according to media reports.

Tunisian President Moncef Marzouki, part of a secular party in the governing coalition, called the assassination a threat against all Tunisians in a speech before the European Parliament in Strasbourg. He then rushed home, canceling a trip to Cairo. “All these destabilization attempts – and there will be others because for some the Tunisian model should not succeed – I can tell you that we will face the challenge and defeat it,” he told journalists.

Ennahda leader Rachid Ghannouchi told the Associated Press that Belaid’s slaying was an “ignoble crime” and urged authorities to bring the perpetrators to justice. He also offered his condolences to Belaid’s family and followers and called for a day of mourning.

Belaid, a leading member of a leftist alliance of parties known as the Popular Front, was shot as he left his house in Tunis Wednesday morning, and died at a nearby medical clinic. His wife Basma told French Radio RTL he was shot twice in the head, once in the neck and once in the heart.

Belaid’s funeral is scheduled for Friday and the family has said members of the ruling coalition will not be welcome.

Several opposition parties reacted by suspending their participation in the elected assembly and are now calling for a general strike.