A law that bans people from soliciting sex from minors or minors from soliciting adults via Internet dating sites was enacted Friday after being approved by the House of Councilors.

Politicians hope the law, which takes effect within three months, will help reduce child prostitution and blackmail cases that have been on the rise due to growing access to sex service Web sites from Internet-capable mobile phones.

A fine of up to 1 million yen will be imposed on an offender regardless of age or sex under the Law Concerning Regulations of Acts to Induce Children via the Internet to Introduce People of the Opposite Sex.

The law is aimed at Internet sites that provide information on how to meet people of the opposite sex and then puts them in contact, generally via e-mail.

By law, minors are defined as less than 18 years old. The new law bans the solicitation of sex from people below the age of 18, as well as soliciting by 18 year olds of people who are willing to pay for dates.

Some opposition lawmakers have objected to the law, arguing that it is out of step with the Child Prostitution Prevention Law, which defines people under the age of 18 as "victims" and states they cannot be punished.

The National Police Agency has called for a ban on online soliciting, saying that more than nine out of 10 child prostitution cases were prompted by approaches from children.

Critics also argue the definition of Internet sites subject to the regulations is vague and could undermine the privacy of communications.

The NPA is planning to offer more detailed instructions on the definition of "introduction businesses" and the enforcement of the new law.