GENEVA — Indigenous communities in Africa are "on the brink of destruction" due to the expansion of national game parks and insufficient law enforcement, a United Nations expert said on Tuesday.

Rodolfo Stavenhagen, a special rapporteur on the human rights and fundamental freedoms of indigenous people, said reserves in countries such as Kenya and Botswana had disrupted hunter-gatherer and pastoralist populations, such as the Maasai.

Many of the countries have enacted laws formally entrenching the rights of indigenous populations in maintaining their lifestyles and culture, but their governments have done little to uphold them, he told journalists in Geneva.

"(Indigenous) communities are on the brink of destruction, of dispersal," Stavenhagen said. "Not enough is being done to protect their rights."

Such populations have also come under pressure in Cambodia, Thailand, the Philippines and large swathes of Latin America as a result of the expansion of mining, oil exploration and other extractive activities, Stavenhagen said.

There are about a quarter of a billion indigenous people. They make up some four percent of the world’s population, but their numbers are shrinking as many assimilate into popular culture.