Media playback is unsupported on your device Media caption Dr Julie Bishop: 'Something we should be concerned about'

Children are nearly twice as likely to try e-cigarettes rather than tobacco, Cardiff University research has said.

A paper published in the BMJ Open questioned 32,479 11-16 year olds in Wales.

While 18.5% said they had tried e-cigarettes, only 10.5% said they had smoked tobacco.

One Swansea e-cigarettes firm said it operated a "challenge" policy to people who looked under 25 to ensure products were not sold to young people.

Jon Nelsey, from ECigaretteDirect, said: "The vaping industry is here to stay and we want to be a reputable retailer. We don't want to be selling to youths. We don't think it's right."

The research said that while there was no evidence e-cigarettes made young people more likely to smoke, "youth e-cigarette use may become a public health issue if left unmonitored".

Smokers, ex-smokers and non-smokers were all questioned as part of the study, undertaken in 2015.

Of those questioned, 2.7% used e-cigarettes at least weekly and 41.8% of those who smoked daily also used them on a regular basis.

Elen de Lacy, lead author of the study, said: "Our data suggest that e-cigarette use is rapidly increasing among youths.

"Regular use by non-smokers remains very low, but is growing.

"The real need now is for further research to examine long-term youth e-cigarette and tobacco use and to understand e-cigarette use from young people's perspectives."

The findings said while those trying e-cigarettes had "grown rapidly" since 2013, most young people who had used both e-cigarettes and tobacco tried the latter first.

Media playback is unsupported on your device Media caption Jon Nelsey, from ECigaretteDirect: "We don't want to be selling to youths. We don't think it's right"

Dr Julie Bishop, from Public Health Wales, said young people using e-cigarettes on a regular basis "is something we should be concerned about".

A Welsh Government spokesperson said it was "disappointing to see that experimentation with e-cigarettes is increasing amongst young people".

The spokesperson added: "Nicotine can cause addiction and harm the developing adolescent brain, which is why we are working to prevent the use of e-cigarettes by children and young people.

"This includes the current age of sale legislation and restrictions on advertising."