Chinese drivers may be stopped by traffic police and asked to open their mouths to allow police to collect samples of their saliva for drug testing.

The China Narcotics Control Foundation received a batch of instant saliva test kits worth about 3 million yuan ($480,000) from the Institute of Biophysics under the Chinese Academy of Sciences on Friday.

The kits will be used by traffic police and narcotics units, according to a statement from the foundation, which is supervised by the Ministry of Public Security.

A test kit consists of a mouth and gum swab for collecting saliva samples. It also contains a tester that can tell whether a person has been using drugs, as well as identify what kind of drugs, in a matter of seconds.

Compared to traditional urine tests, the saliva test is easier to use and will greatly improve the efficiency of police work, the statement said.

Last April, a coach collided with a truck on an expressway in east China's Jiangsu Province, killing 14 people and injuring 20 others. The driver was found to have been using crystal meth.

The accident triggered a national program to test coach drivers for drug use, resulting in about 1,400 coach and truck drivers having their licenses suspended over drug use.

China had a total of 2.14 million registered drug users as of March, up 19 percent from 2011, according to the foundation.

Drug-related crimes have become more complex in the past few years, as the sources and types of drugs have become more diverse and the average age of drug users has noticeably dropped, the statement said.