The number of 15-year-olds in Scotland who regularly smoke has fallen to 7%, while 2% of 13-year-olds are frequent smokers.

The proportion of 15-year-olds smoking regularly fell 2% between 2013 and 2015, while the rate for 13-year-olds remained steady, according to the latest Scottish Schools Adolescent Lifestyle and Substance Use Survey (Salsus) which questioned 25,304 pupils at 264 schools.

The age that 15-year-olds who have smoked first tried a cigarette has risen to 13 years and four months.

The schoolchildren reported a large increase in trying e-cigarettes, with 15% of 13-year-olds and 32% of 15-year-olds saying they had done so - but only 1% and 3% respectively used them regularly.

The number of 15-year-olds exposed to second-hand smoke at home fell by 6% to 19% between 2013 and 2015.

The survey found the more deprived an area a 15-year-old lived in, the more likely they were to smoke regularly, and those with poor mental health, illness or disability were also more likely to be frequent smokers.

One in five 13-year-old regular smokers said they bought their cigarettes from shops, while 29% of 15-year-old smokers said the same. The most common source of cigarettes for both ages groups was getting someone else to buy them for them.

Sheila Duffy, chief executive of anti-smoking charity Ash Scotland, said there is "no excuse" for shopkeepers to sell tobacco to children.

She added: "Fewer children than ever are now taking up smoking, putting us well on the way to a tobacco-free Scotland by 2034. We need to keep up the pressure so no child becomes addicted to tobacco, and make sure that the best help to quit is available for those who've already started.

"In line with other recent measures, we've seen a drop in exposure to second-hand smoke among children. That's good news, and chimes with the enthusiastic reception of the Take it Right Outside campaign.

"But the job's not over - 19% of 15-year-old children are still exposed to dangerous second-hand smoke in the home on a regular basis. We need to raise awareness and encourage voluntary effective protection."