The health ministry set up special units in January to crack down on illegal drug trade on the Internet, with investigators arresting about 60 people in the seven-month period through July, government sources said Friday.

The number of arrests made by the teams under the Health, Labor and Welfare Ministry is significant because only about 10 people were nabbed for such allegations in all of 2004, the sources said.

The special teams belong to the ministry's eight regional bureaus across Japan in cities that include Sapporo, Nagoya, Osaka and Fukuoka.

Investigators posing as potential customers of illegal drugs placed buy orders on the Internet in undercover operations, after conventional investigative tactics, including stakeouts, proved ineffective in clamping down on Internet sales, the sources said.

Dealers on the Internet usually accept orders via e-mail or mobile phone and the drugs are shipped to buyers after the money was remitted to the dealers' bank accounts, health ministry officials said.

People can purchase illegal drugs easily on the Internet because orders can be placed anywhere and without contacting dealers in person, the officials said.

They said the expansion of Internet trade has attributed to the rise in drug abuse, especially among youth. The narcotics squads in the eight regional bureaus had placed Web sites and Internet message boards suspected of being linked to drug sales under closer surveillance for years, and determined the proliferation of such deals warranted the special teams.