Nairobi (AFP) - A top Tutsi general was gunned down in Burundi on Monday, as international prosecutors announced they were launching a preliminary probe into a litany of atrocities in the troubled central African nation.
A wave of unrest, targeted assassinations and alleged torture has left hundreds dead and forced more than 270,000 to flee the country since last April, and some analysts warn Burundi may be on the brink of a new civil war.
General Athanase Kararuza, a security advisor to one of Burundi's vice presidents, was killed along with his wife in a gun and grenade attack as they were dropping their daughter off at school in the capital Bujumbura.
UN Secretary-General Ban Ki-moon led international condemnation, saying: "All such acts of violence serve no purpose other than to worsen the already volatile situation in Burundi."
A family source said Kararuza's daughter was seriously injured but her life was not in danger, contradicting a Burundian security source that earlier said she too had died.
Kararuza was a former commander of the African Union-led peacekeeping force in the Central African Republic. It was not clear who carried out the assassination.
"Those who killed my colleague General Kararuza and (carried out) other similar attacks are trying to sow divisions in the army and the police," presidential spokesman Willy Nyamitwe wrote on Twitter.
On Sunday a police colonel, also a Tutsi, was seriously wounded in an attack, while Human Rights Minister Martin Nivyabandi and his wife had a close escape from a grenade assault as they left church.
- ICC probe -
The latest spasm of violence in a country with a troubled ethnic history was triggered when President Pierre Nkurunziza decided last year to run for a third term in office.
His move sparked weeks of street protests and a failed coup, but he went on to win an election in July that was slammed as anti-constitutional by civil society and the opposition.
Shortly after Monday's killing, the chief prosecutor for the International Criminal Court announced she was launching a preliminary probe into the crisis.
Fatou Bensouda said she had warned that "those alleged to be committing crimes falling within the jurisdiction of the International Criminal Court could be held individually accountable".
Her office had reviewed reports "detailing acts of killing, imprisonment, torture, rape and other forms of sexual violence, as well as cases of enforced disappearances".
"All these acts appear to fall within the jurisdiction of the ICC," she said.
The initial probe is aimed at determining whether there is enough evidence to proceed to a full-blown investigation, which could result in charges against any alleged leaders of the violence.
The European Union described Mkapa's announcement as a "step in the right direction".
Former Tanzanian president Benjamin Mkapa said he wanted to relaunch moribund peace talks in May.
- 'Civil war has begun' -
The international community -- still traumatised by the 1994 genocide in neighbouring Rwanda in which an estimated 800,000 people died, mostly Tutsis -- has grown increasingly alarmed by the unrest in Burundi.
There have been calls to avert a possible genocide and a repeat of its 1993-2006 civil war, which left some 30,000 people dead.
The EU has even suspended its aid to Burundi's government, a vital lifeline for a country the IMF deems the world's poorest with a per capita annual income of just $315.2.
The opposition, as well as civil groups and some of Nkurunziza's own supporters, accuse him of violating the constitution and the Arusha peace deal that ended the civil war.
While Tutsis are the most vocal critics of the president's power grab, the current crisis is above all political in origin, with the anti-Nkurunziza front cutting across ethnic lines.
Over the past year, numerous politicians, civil society leaders and army officers have been killed or narrowly escaped attacks, with both sides systematically denying any responsibility.
Robert Besseling of intelligence firm Exx Africa warned Burundi was already sinking into a new civil war.
"Rival sides in the conflict have become entrenched and violence has become more brutal," he said.
"In fact, in many ways, a civil war has already begun given the ethnic tinge to the most recent violence, especially in the countryside."