LONDON - Industrial development is posing threats to close to half of the world's natural heritage sites, a new survey by the conservation charity WWF (World Wildlife Fund) said on Wednesday.

The sites are all supposed to be protected under the United Nations' designated world heritage status. However, fossil fuel exploration, illegal logging and other industrial development are endangering these sites.

At least 114 of the 229 world heritage sites known for their natural habitats or their flora and fauna are at risks, according to the report.

The WWF findings are stunningly higher than the 18 natural sites listed as "in danger" by the World Heritage Committee of the UNESCO.

David Nussbaum, chief executive of WWF-UK, said these areas "contribute to our economies through tourism and natural resources, providing livelihoods for millions of people."

They deserve better protection of the humanity, he said.