Official estimates place the number of drug abusers in China at well over 10 million, with the majority of them being teenagers, an official with the country's top drug control authorities said on Wednesday.

Liu Yuejin, head of the Narcotic Control Bureau of the Ministry of Public Security, told China Central Television in an exclusive interview that public security authorities have identified over 2.4 million drug abusers, but far more remain unknown to the authorities.

According to international practice when formulating a census of drug users, Liu said that the actual number of drug abusers in China should be around 5 times bigger than the currently identified number.

China has also seen a rising number of teenage drug abuse cases, with more rural teenagers, who have been left in the countryside by their migrant parents, becoming addicted, said Liu.

He added that the number of teenage drug abusers accounts for over 70 percent of the total amount.

The growing number of rural teenagers left at home who have reportedly been taking drugs while their parents seek jobs in cities is noticeable, Liu said, saying that the absence of parental guidance and lack of knowledge about the harmful consequences of drugs are the key reasons for the problem.

"They often seek fun on the Internet, which is the key platform where they buy or sell such substances," said Liu.

According to Liu, synthetic drugs such as methamphetamine and ecstasy have gained popularity among young drug addicts.

"Compared to those drugs which are derived from plants, synthetic drugs are much cheaper and fast-acting, which make them attractive to young people," Du Xinzhong, a Zhejiang-based drug expert, told the Global Times on Thursday.

Many young addicts he has been in contact with were under the impression synthetic drugs have lower risks compared to other drugs, Du said.

However, in fact, such drugs can be highly addictive and cause damage to their health, he added.

"Synthetic drugs are easier to make and come in many varieties, which makes it difficult for the authorities to crack down on them. Online sales of the drugs make it more difficult to trace the trafficking," said Du.

The country has put effort into cracking down on online drug sales. Public security authorities in Hainan Province in 2011 uncovered an illegal narcotics ring that sold substances through social networking and video websites, the first of its kind in the country, the Beijing-based Legal Daily reported.

However, Du noted that strengthening drug education and improving community supervision over those teenagers are more important aspects of solving teenage drug abuse problems.

In the same media report, Liu also said that as international illegal drug dealing is a serious issue, China still faces tough challenges in anti-drug campaigns this year. He added that drug-related crimes in China are often associated with violence and the illegal possession of guns.

China has also vowed to conduct comprehensive anti-drug campaigns in 2014 by enhancing supervision over postal and transport networks.