More teenagers are becoming sexually active - with an increasing number thinking that it is normal for them to have sex, social workers say.
Figures from the State Courts show a steady growth in the number of cases of sex with a minor - that is, sex with a girl under 16, which is a crime even if she gives her consent.
Last year, there were 76 cases of the offence, down from 89 in 2013, but still an increase from 63 in 2012 and 36 in 2011.
At the Youth Court - which deals with children and youth under 16 years - there were four cases of youths charged last year with having sex with another minor, and five cases of assault with the intent of molest.
Social workers told The Straits Times that young people are typically referred to counsellors for behavioural problems but, during counselling, they sometimes open up on their sexual experiences.
Ms Lena Teo, assistant director of counselling at the Children-at-Risk Empowerment Association (Care Singapore), said: "I've seen roughly 20 per cent more underage sex cases over the years. Nowadays, teens are more tech-savvy and some lack parental control. They are more experimental because of curiosity and hormones raging at that age. It could also be peer pressure."
Mr Lam Wai Mun, a senior counsellor at Touch Cyber Wellness, noted that underage sex is a common issue.
"Some in primary school are also watching pornography, which is damaging because they form unhealthy perceptions," he said.
The younger generation is also more open to having sex at an early age, according to Mr Trevor Xie, former director of Children's Wishing Well, a charity for underprivileged children and youth.
"They don't see losing their virginity as a loss. They see sexual experience as a gain," he said.
Mr Xie added that they are usually willing parties, and are looking for love.
Ms Rachel Lee, senior assistant director of Fei Yue Family Service Centres, said the Internet has an impact on their views on sex as they may be exposed to "undesirable material" online.
"In the last five years or so, there has been an increase in such cases. There are those who engage in underage sex but are just not caught yet," said Ms Lee.
"This affects their studies and some may get pregnant and drop out of school," she said, adding that "a lot of them are not ready to take on the responsibility".
Experts said parents play an important part in ensuring that their children grow up with the right values.
Ms Gracia Goh, head of the Singapore Children's Society's youth centre in Jurong, advised parents to talk to their children about sex and take note of any inappropriate behaviour. Parents should also look for "teachable moments" when they can have discussions with their children about what they are watching or hearing, added Ms Goh.
If necessary, they can block access to websites with sexually explicit material.
Dr Adrian Wang, a psychiatrist in private practice, advised: "Have a close and healthy relationship with your children, so that they'll feel comfortable asking you questions, and you'll know who their friends are and what they've been up to.
"Peer influence is a powerful thing, and many kids are clever enough to go under the radar and hide their activities from you."