Some refugees say they are running from the Imbonerakure, a fearsome group whose name means “The Watchmen” or, literally, “Those Who See Far”.
The militia acts in support of President Pierre Nkurunziza, whose bid for a third term has triggered weeks of sometimes violent protests in the capital Bujumbura.
Among those who have sought safety in neighbouring Rwanda are people who described gangs of thugs going house to house, daubing doors of suspected opposition supporters with red paint as a grim warning of attacks to come.
“The Imbonerakure came to our neighbourhood to say that those who were against the third term of President Nkurunziza were going to die, that’s why I left,” said Eric Ahishakiye, a 23-year old mechanic.
Burundi, where a 13-year civil war between ethnic Tutsis and Hutus ended in 2006, has been rocked by violent protests since the ruling CNDD-FDD party designated Nkurunziza as its candidate in elections due next month.
Critics say a third term for Nkurunziza runs counter to both the Constitution and the Arusha accords that ended the war.
At least 19 people have been killed and scores wounded since late April.
Marked with red paint
Nkurunziza, a former rebel leader from the Hutu majority, has been in power for a decade and has so far defied international pressure to withdraw from next month’s election.
Beyond the street protests challenging Nkurunziza’s third-term bid, the bigger worry is that the current crisis could jeopardise the Arusha Agreement, which brought peace to Burundi.
The deal included an ethnic power-sharing formula that helped end the war between the mostly Tutsi army and predominately Hutu rebel groups.
UN refugee agency spokesman Adrian Edwards said those fleeing recounted “harassment and intimidation by Imbonerakure youth militants, who paint red marks on homes of people to be targeted”.
Since early April over 50 000 people, mostly women and children, have fled Burundi with at least half of them going to Rwanda, according to the UN refugee agency.
Almost 18 000 have fled to Tanzania and 8 000 to the Democratic Republic of Congo.
The Imbonerakure, a Hutu group affiliated with the CNDD-FDD rebels turned ruling party, has a bloody reputation: in February, Human Rights Watch accused security forces and the Imbonerakure of together executing at least 47 rebel fighters who had surrendered.
Members of the youth wing were accused of beating to death those prisoners who were not shot, of throwing others off a cliff and of helping to hide bodies in mass graves.
Forced to flee again
Rwanda, where a Tutsi-led government has been in power since the 1994 genocide by extremist Hutu killers, has signalled its concern at the arrival of so many refugees.
“While we respect Burundi’s sovereignty in addressing internal matters, Rwanda considers the safety of innocent populations as a regional and international responsibility,” Foreign Minister Louise Mushikiwabo said last week.
Burundi has rejected Rwandan concerns that some of the violence was linked to Rwandan ethnic Hutu rebels of the Democratic Front for the Liberation of Rwanda (FDLR) – a group Kigali has previously sent troops into DR Congo to target.
Refugees in Rwanda are made up of both Hutus and Tutsis.
Ahishakiye, the mechanic who fled home, said he was Hutu and a member of the Tutsi-dominated UPRONA opposition party so for him, the threats were about politics, not ethnicity.
“We are mixed here. I cannot distinguish who is Hutu or Tutsi, we are the opposition,” he said. “Even within political parties we are mixed.”
Ahishakiye said he chose Rwanda because it was the closest safe place he could find.
“In this camp there are Tutsi, but all ethnic groups are represented,” said Jacqueline Nibony, 50, sitting on a mat in front of a plastic shelter, cradling her four-year old daughter whose body was wracked by coughing fits.
“I heard on the radio that there would be war in Burundi,” Nibony added, surrounded by a dozen women who nodded in agreement. “Whoever is afraid, fled the country.”
“It is clear Nkurunziza will not give up his third mandate,” said Ndagijimana Diomedes, a 38-year old supporter of Agathon Rwasa, another former Hutu rebel leader and Nkurunziza’s main challenger.
“But the demonstrators will not give up,” said Diomedes who fears a return to the ethnic violence that sparked the civil war leading to the deaths of 300 000 people.
Diomedes fled Burundi after post-election violence in the last polls in 2010, running that time to Tanzania and returning six months later.
“Now war comes again, and I am forced to flee again,” he said. – AFP