Some militant groups have taken things into their own hands on occasion by, for example, attacking unlicensed churches and bars selling alcohol during the Muslim fasting period.

"I am afraid to sell the first edition because it has been reported that the Islamic organizations would be on alert," said newsstand owner Ronni, 30, who operates near the headquarters of a hardline Muslim group, the Islamic Defenders' Front (FPI).

Tubagus Sidiq, a senior leader of FPI, told Reuters: "FPI opposes (Playboy) in whatever form."

"According to our commitment, if they don't withdraw it then we will act in our own way, the forceful way. Our crew will clearly hound the editors ... We even oppose the name Playboy."

The government took a different view.

"The laws that we can use in this case (are) whether there is a publication that violates decency. So, we need to check the content first. Just using the name is insufficient to ban it," Information Minister Sofyan Djalil told reporters.

Bambang Kuncoko, a national police spokesman, said at a news conference that "the public should follow the law and must not take arbitrary actions. If that happens, the police will absolutely take legal actions."

Late Friday afternoon about 20 FPI protesters, outnumbered by journalists covering them, showed up at the Playboy publishers offices, and local news radio said a representative team met with the magazine's editors.

Despite regular campaigns against pornography, many sidewalk vendors in Indonesia stock sexually explicit movies and the country has a flourishing sex industry.

Founded in 1953, Playboy has about 20 editions around the world that cater to local tastes.