A Burundian rebel group claimed responsibility Friday for a spate of recent attacks on security forces and the ruling party's youth league that it said had killed dozens.
The RED-Tabara group said it had between Sunday and Thursday engaged soldiers and police as well as members of the Imbonerakure youth league, which is often referred to as a militia.
Its spokesman Patrick Nahimana told AFP they had killed "28 soldiers and police and 15 militia members, and injured 40" in the western province of rural Bujumbura, southwestern Rumonge and southern Bururi.
The exact toll could not be independently confirmed.
Nahimana said three members of his group, Resistance for the Rule of Law-Tabara (which means "to help" in the local Kirundi language) were killed, and one captured.
The attacks, which follow others in previous weeks in the same areas, are part of what the group described as an "offensive" launched in mid-August against the "dictatorial" ruling CNDD-FDD.
RED-Tabara first appeared in 2011, and has been based in the South-Kivu province of neighboring Democratic Republic of Congo, and has carried out sporadic attacks on Burundian soil in recent years.
Fighters with the group arrived in Burundi via Lake Tanganyika on August 22, according to witnesses, whose accounts were confirmed by the governor of Rumonge province.
Burundi's only independent media outlet, Iwacu, earlier this month declared "the specter of rebellion" hung heavy after a slew of shadowy assaults by unknown gunmen.
Fighting 'criminal system'
Nahimana said the group was "fighting against a criminal system which kills, pillages the country," referring to the ruling party.
Former president Pierre Nkurunziza died in June after 15 years in power, and he has been succeeded by Evariste Ndayishimiye.
However, hopes of change under a new president, after years of political crisis, have been dashed.
U.N. investigators said Thursday that rights abuses have continued and those sanctioned for their involvement in such violations had been appointed to senior positions.
Thierry Vircoulon, a researcher at the French Institute of International Relations, said RED-Tabara's new offensive was meant to "show the new president that they exist, that he will have to deal with them."
"At this stage their numbers are too small to represent a real threat to the Burundian government," he said, adding that they did appear to have "more capacity than before."