Sunbeds, used in indoor tanning sessions, may put people at increased risk of melanoma – the most dangerous type of skin cancer, a new study has warned.

Melanoma has the strongest increase in incidence in the last decade, and the incidence rates have never been as high as in 2014, researchers said.

The World Health Organisation (WHO) based International Agency for Research on Cancer has classified UV-emitting tanning devices as "carcinogenic to humans" in 2009.

However, sun-bed use is still popular in western countries, especially among young women.

The study by University of Oslo followed 141,000 Norwegian women for the average of 14 years.

Women who had 30 or more indoor tanning sessions were at 32 per cent increased risk of melanoma compared to never-users.

In addition, women who started indoor tanning before age 30 were on average two years younger at melanoma diagnosis than never-users.

These associations remained significant after controlling for age, birth-cohort, ambient ultra-violet (UV) radiation of residence, hair colour, skin colour and cumulative number of sunburns and sunbathing vacations.

Modern sunbeds emit six times more UVA and twice as much UVB as the Oslo summer sun, researchers said.

The findings of this study have important implications for public health, as it shows that sun-bed use increases the burden of melanoma in societies by both increasing the number of patients and decreasing the age at diagnosis.