He said Thai net surfers did more than 520,000 searches using the keyword "sex" in January alone.

The scenario prompted the government to announce a "good society for children" policy with a national committee on safe and constructive media to oversee television, radio, telephone services, the Internet and movies.

Paiboon, the social development and human security minister, said Thailand had about 500,000 web pages containing inappropriate and sexually obscene content which young people could easily access.

What seemed to spread most quickly were video clips featuring young women in revealing clothes, he said, citing an obscene video clip featuring an actress look-alike which had received nearly 300,000 online searches in the past two weeks.

An initial investigation had found there were at least 250 websites that featured obscene and nude clips of teenagers.

"Thai youths and children thus become both the performers and the audience. When connected to the Internet, it takes only 25 seconds to access inappropriate websites such as pornography, which is different from the past when it took a lot longer to find a porn book or sex video," he said.

Citing a recent study that said Thai children mostly used the Internet to see obscene material followed by VCD movies and books, Paiboon said inappropriate Internet content could lead to sexual violence and crime among youths who were being constantly stimulated.

The Internet was also a channel for criminals to lure the innocent, he said, citing the cases of 19 children aged 13 to 15 being reported to the Mirror Foundation's Missing Person Centre.

On many of the obscene websites were commercial banners promoting the 1900 telephone service and messages urging people to call a number to exchange sexual experiences or get together with "students providing sex services as a sideline", he said. About 10 kids had been reported as missing after making contact with strangers via the phone services, Paiboon added.

"I have to talk about this because it's now a factor in youth problems," he said, adding criminal gang elements appear to be involved.

The National Electronics and Computer Technology Centre (Nectec) had reported that half of Thailand's 8.4 million Internet users last year were young people under 25. It predicted this year there would be 13 million Internet users and 6.5 million of them young people, Paiboon said.

Nectec also said Thais last year looked up the key word "sex" 5.8 million times and this January there were 520,000 searches.

Paiboon said the public could provide opinions and suggestions on his personal web blog at http://gotoknow.org/blog/paiboon.