Both rebel groups and the military in Burundi are denying responsibility for the ambush and murder of at least 17 people in the northwest part of the country Wednesday.
The leader of the National Liberation Forces, Pasteur Habimana, told VOA his group is not responsible for Wednesday's ambush in the province of Cibitoke, in which 14 school children and three others were killed. Two more people reportedly died later.
"We condemn the killings of innocent children," he said. "School children are not involved in the fighting. Why should one ambush a bus carrying school children?"
Mr. Habimana blames the Burundian government and the country's main rebel group, the Forces for the Defense of Democracy, for the attacks.
In turn, army spokesman Colonel Augustin Nzabampema and FDD spokesman Gelase Ndabirabe told reporters they were not involved in the attacks.
Information consultant Aissatou Soumare, who works for various humanitarian agencies, says determining who is responsible for the ambush is a difficult task.
"Now, there are a lot of ambushes happening here in Burundi," he said. "It's mixed. Sometimes it's the rebels, sometimes it's the armed bandits, so you cannot just say who did exactly this act."
Thursday's ambush took place less than a week before regional leaders, along with Burundian President Domitien Ndayizeye and FDD leader Pierre Nkurunziza, are to meet in Tanzania to revive Burundi's peace process. The meeting is scheduled for September 15.
A meeting that was supposed to take place in Kampala Thursday between President Ndayizeye and Mr. Nkurunziza was canceled. According to the French news agency, AFP, both sides wanted to consult further before having face-to-face talks.
An interim government was set up in November 2001 in an attempt to bring peace to Burundi after 10 years of civil war and, last October, a peace deal was signed between the government and a Hutu-dominated FDD faction. But, despite the fact that the current interim president is a Hutu, the National Liberation Forces refused to sign the deal.