A group of six park rangers was ambushed and killed at Virunga National Park in the Democratic Republic of Congo (DRC). The park, home of about a third of the world’s mountain gorillas, has been subject to repeated attacks over the years from poachers, loggers, rebels, and militia groups, with no clear solution in sight.

The attack was attributed by DRC officials to Mai-Mai fighters — an umbrella name for a loosely affiliated group of local militias who are fighting for power and resources in Congo. Two of the fighters were killed alongside the six park rangers. In addition, a ranger was seriously injured and is currently recovering at a local hospital.

The wardens were patrolling on foot in the morning near the town of Kabuendo when they were taken “by surprise” by the attackers and had “no opportunity to defend themselves,” the park said in a statement. All of them worked for the Institute for the Conservation of Nature, the agency in charge of safeguarding protected areas.

The park authorities said they lamented the “tragic loss of life” among the rangers, who “work tirelessly and with dedication to protect both the park and the neighboring communities from the tyranny of armed groups.” In a statement, they said that “the sacrifice” of the group of rangers “will not be forgotten nor be in vain.”

The assault against the park and its rangers comes only a year after a group of assailants killed 17 people in the same park. The victims included 12 park rangers, four civilians, and a driver. Virunga’s director, Emmanuel de Merode was shot and injured in 2014, and tourists have been repeatedly kidnapped during arranged visits to the park.

With a population of over 100 million, the DRC is Africa’s second-largest territorial state after Algeria and is almost seven times the size of Germany. It’s also home to the largest remaining rainforest areas in Africa. Virunga park was created in 1925, covers some 7,800 square kilometers (3,000 square miles), and houses a quarter of the world’s mountain gorillas — but it’s also home to some of the world’s most violent guerilla groups.

Mountain gorillas have been struggling for decades, with their forests destroyed by deforestation, civil war, and agriculture expansion. As a result, the population has significantly diminished and their population remains threatened. Conservation efforts such as the one carried out in Virunga has raised hope for the species but poachers remain as a big problem.

The park is guarded by almost 700 armed rangers, at least 200 of whom have been killed in the line of duty over the past decade. It draws thousands of visitors per year, making it the top tourist destination of DRC. Many got inspired by the 2014 documentary “Virunga,” which tells the story of the park and its protected gorillas.

Virunga decided to shut down for almost a year after a local guide and two British tourists were kidnapped in 2018. It reopened in 2019 with more strict security measures and following an audit. Visits only last an hour and tourists have to have a surgical mask in the presence of gorillas to minimize the risk of disease transmission between the two species.

The DRC authorities also took measures to improve security in all its national parks, creating a special force in charge of securing national parks (CorPPN). They have been deployed in the five DRC World Heritage sites, including Virunga. Still, violence prevails, as seen with this new assault, which forces to rediscuss the approach.