Extraordinary causes sometimes require extraordinary measures, and so it was that four young gorillas found themselves being airlifted to sanctuary last month. UN peacekeepers used helicopters to fly the apes from a battle zone in the Democratic Republic of Congo. The gorillas had been rescued from traffickers in the country's rebel-infested east and faced being eaten.

These animals are eastern lowland gorillas – a species that only survives in the DRC – and were flown from Goma to the Kasugho sanctuary in North Kivu province. The use of air transport was crucial to the mission, conservation experts insisted. "If you use vehicles, there is a great risk of losing the animals because they are traumatised. We used aircraft because we really wanted to reduce their stress level," said Benoit Kisuki, country director of the charity Conservation International.

The rescue project is part of a larger mission which has been set up to combat Africa's illegal trade in baby gorillas. This has intensified in recent years with the proliferation of armed groups in the DRC. Gorillas are often caught and sold for thousands of dollars as exotic pets. Others are killed and sold locally as "bush meat". Today only 5,000 eastern lowland gorillas are thought to survive in the wild.

The rescued gorillas have been given homes at a research centre where scientists can monitor their health before releasing them back into the wild. A further six gorillas, currently under protection in Rwanda, are due to be flown to the sanctuary on 10 June to "socialise" with the first group.

Conservationists say these great apes could become a valuable asset for the future economic development of the region. Gorillas have become a major tourist attraction in Uganda and Rwanda. By contrast, Congo's gorillas have suffered the effects of years of warfare and more than 150 rangers have been killed trying to protect the area's five national parks from poachers.

A new UN-backed report says gorillas may become near-extinct in Africa's Greater Congo Basin by the mid-2020s unless action is taken to stop poaching and protect their habitat.