Hutumilis is identified as responsible for the attack - described as the deadliest in the park's modern history.
About 60 people from the FDLR militia group struck in an ambush against a column of civilians, protected by 15 guards, according to the head of the Congolese natural authority ICCN.
Virunga is Africa's oldest national park and is classified as a World Heritage Site by the UN agency Unesco. It opened in 1925 and is a popular tourist destination most known for its mountain gorillas. The park is located in the seriously violent province of Nordkivu, where poachers are also a constant threat.