The use of cell phones and other wireless communication devices are "possibly carcinogenic to humans", the World Health Organisation's (WHO) cancer research agency said Tuesday.

The radio frequency electromagnetic fields generated by such devices are possibly cancer-causing "based on an increased risk for glioma, a malignant type of brain cancer," the International Agency for Research on Cancer (IARC) said in a statement.

A group of 31 experts meeting in Lyon, France over the past days "reached this classification based on its review of the human evidence coming from epidemiological studies," said Jonathan Samet, president of the work group.