Rangers in the Democratic Republic of Congo's Virunga park have a new weapon in their fight against poachers.
National Park authorities have trained five bloodhound dogs to track elephant poachers after a spate of incidents.
The first investigation using the dogs was carried out last week and led to the discovery of illegal weapons.
Poaching is one of the key threats to the animals in Virunga, a Unesco World Heritage Site in the war-torn eastern region of DR Congo.
The park is also home to gorillas, chimpanzees, okapi, forest elephants and buffalo, among other wildlife. Some 300 rangers protect the park from poachers, rebel groups and illegal miners.
Park authorities now hope the bloodhound programme, which was implemented with help from a specialised Swiss centre and volunteers from the German police, will help to protect the vulnerable elephant population from ivory poachers.
The dogs and their handlers got the chance to put their training into action on 1 March, when rangers spotted a dead elephant with its tusks cut off on the edge of Virunga.
They deployed two of the bloodhounds by helicopter, along with a specially trained ranger unit.
The dogs tracked the poachers' scent for seven kilometres (four miles), leading to a small fishing village.
After patrolling the area, rangers encountered a group of poachers who fled after opening fire, leaving their weapons behind.
Emmanuel de Merode, the Virunga National Park's chief warden, said: "We are extremely pleased with the outcome. After a year of intensive training, both the hounds and the rangers proved to be a very effective weapon against ivory poachers."
Park rangers will continue to work with the canine unit as part of a wider European Union-funded project to protect wildlife in a park officials say is heavily infiltrated by armed groups.