Updated

Muslim clerics are seeking ways to regulate online behavior in Indonesia, saying the exploding popularity of social networking sites like Facebook could encourage illicit sex.

Around 700 clerics, or imams, gathering in the world's most populous Muslim nation on Thursday were considering guidelines forbidding their followers from going online to flirt or engage in practices they believe could encourage extramarital affairs.

Facebook says Indonesia, a nation of 235 million, was its fastest-growing country in Southeast Asia in 2008, with a 645 percent increase to 831,000 users —outpacing China and India. And with less than 0.5 percent of Indonesia's citizens wired, there is a huge potential for growth.

"The clerics think it is necessary to set an edict on virtual networking, because this online relationship could lead to lust, which is forbidden in Islam," said Nabil Haroen, a spokesman for the Lirboyo Islamic boarding school, which is hosting the event.

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Though followers could still be members of the networking site, guidelines dealing with surfing the Web and Islamic values are urgently needed, he said.

Facebook officials did not immediately respond to a request for comment.

Ninety percent of Indonesians are Muslim, though most practice a moderate form of the faith.

An edict by the clerics would not have any legal weight. But it could be endorsed by the influential Ulema Council, which recently issued rulings against smoking and yoga. Most devout Muslims adhere to the council's rulings because ignoring a fatwa, or religious decree, is considered a sin.

Amidan, who heads the Ulema Council, said the growing number of Facebook users in Indonesia was a controversial subject among Muslim leaders and that he favored a ban because of possible sexual content.

"People using Facebook can be driven to engage in distasteful, pornographic chatting," said Amidan, who was monitoring the two-day conference in the town of Kediri, in eastern Java.

Many clerics are concerned that "inappropriate content" on Facebook could be accessed by children, said Amidan, who like many Indonesians goes by a single name.

Facebook is the top ranked site in Indonesia, ahead of search engines Yahoo and Google, according Alexa.com, which tracks Internet traffic. Nearly 4 percent of all Facebook visitors are from Indonesia, making it the largest source of visitors after the United States, the United Kingdom, France and Italy.