Social tensions and bloodshed in Burundi’s capital, Bujumbura, have soared since the killing of opposition politician Zedi Feruzi on May 23. As of this writing, it remains unclear who is responsible for Feruzi’s murder.

The assassination came only one week after an attempted coup d’état and weeks of demonstrations against President Pierre Nkurunziza’s bid to run for a third term. The killing of Feruzi led to the collapse of UN-sponsored negotiations between the government and opposition parties, and the resumption of daily demonstrations in Bujumbura.

The government has now banned the demonstrations. However, they are continuing and much of the economic activity of the capital has ground to a halt. Already thirty people have been killed by police gunfire. Five radio stations have been shut down by the government for supporting the opposition to Nkurunziza’s third term.

The growing tensions raise the danger of a return to the civil war that raged in the country for 12 years until 2005, in which over 300,000 people died. Ethnic tensions between the Hutus and the Tutsis also threaten to spark a renewed regional war from Burundi to neighboring Rwanda and the eastern region of the Democratic Republic of the Congo.

The day before Zedi Feruzi’s murder, a main market in the center of the capital, Bujumbura, was the scene of a grenade attack killing three and injuring 40 people. Such political assassinations and grenade attacks were frequent during the civil war.

While the conflict in Burundi started as a political one, with escalating divisions inside the ruling Hutu establishment, there are increasing signs that the government is trying to push the conflict along ethnic lines. Hutus make up approximately 85 percent of the population, with Tutsis accounting for the remaining 15 percent.

After Nkurunziza said that ninety-nine percent of Burundi was “calm,” Pascal Nyabenda, the president of the ruling National Council for the Defense of Democracy-Forces for the Defense of Democracy (CNDD-FDD) party, accused the protests of being concentrated in a few Tutsi areas of Bujumbura.

In fact, however, the protests started based on opposition to Nkurunziza’s attempt to run for a third time as president; they found support even within the CNDD-FDD itself. “In the CNDD-FDD, the dissidents, who had signed a letter to express their disagreement, were reduced to silence,” wrote French daily Le Monde. “The divisions were covered over, but the demonstration had been made: the opposition to Pierre Nkurunziza was political and not ethnic.”

General Godefroid Niyombare, who led the recent failed coup, was Nkurunziza’s Intelligence Director until he was fired for writing a report hostile to a third presidential bid by Nkurunziza.

Zedi Feruzi had been one of Nkurunziza’s collaborators in the CNDD-FDD until he broke with him in 2007 and was subsequently arrested, sentenced, and jailed.

The US State Department has issued a statement pressing the government to negotiate a settlement to the conflict. It condemned the killing of Feruzi and the grenade attack in Bujumbura and called for an investigation into the deaths. It also called on the Burundian government to “permit the immediate resumption of broadcasts by independent radio stations, end the use of the term ‘insurgents’ to refer to peaceful protesters, and withdraw the proclamation by the Burundian National Security Council prohibiting future demonstrations.”

Without naming the United States, Burundian government spokesman Philippe Nzobonariba then issued a statement on state radio, declaring: “The government of Burundi is profoundly preoccupied by the current diplomatic activity which could undermine and denigrate our republican institutions and constitution.”

The Burundi unrest now threatens to explode into a broad regional war like the conflict, sometimes referred to as the Great African War, that erupted in Rwanda and the Congo in the 1990s and 2000s. Observers are warning that the Rwandan regime and Hutu “Democratic Forces for the Liberation of Rwanda” (DFLR) militias operating in the Congo could intervene militarily in Burundi if its government collapses.

In the Great African War, Washington trained and backed ethnic Tutsi rebel forces under Paul Kagame to overthrow the ethnic Hutu regime in Rwanda and undermine French imperialist influence in the region. As the Rwandan Hutu regime launched a genocidal attack on Tutsis, Kagame’s forces invaded and overthrew the regime.

The Hutu DFLR militias ultimately fled across the border into the Democratic Republic of the Congo. Forces in the Congo allied to Kagame then played a key role in launching the 1997-2003 civil war in the Congo that undermined the French-backed regime that emerged from the Mobutu dictatorship. Several million people in all were killed in these wars, which involved nearly every country bordering the Congo.

In Burundi, the government’s strategy of stoking up ethnic tensions threatens to spiral out of control at any moment. Filip Reyntjens, a professor at the Anvers University, spoke on Belgian television: “This weekend we have just seen the assassination of a political opponent for the first time in many years. The tension has clearly gone up a level… The President has already said a number of times that he will be a candidate. It is very difficult for Nkurunziza to back down on this. But the opposition will accept nothing other than him standing down as a candidate.”

Reyntjens drew two possible scenarios from his analysis of the situation: either “the party in power will persevere and continue to repress the demonstrations… The regime will become more oppressive than it is today,” or “a certain number of political parties will take up arms again and the civil war in Burundi will start up again. A return of the civil war cannot be excluded.”

Reyntjens concluded that the “borders are so porous that an international extension to the Democratic Republic of the Congo and Rwanda cannot be excluded either. If ever the Hutu rebels of the DFLR in the Congo intervene in the conflict, and there was the impression in [Rwandan capital] Kigali that the Burundi Tutsis were targeted, Rwanda has already said that it would be obliged to intervene.”