Malaysia's police, who have recently cracked down on dissident bloggers and broken up anti-government demonstrations, say that protests over an edict against Muslim women wearing trousers pose a security threat.
Mainly Muslim Malaysia's National Fatwa Council recently issued a religious ruling that wearing trousers was un-Islamic. It said that, by wearing trousers, young girls risked becoming "tomboys" who became sexually active.
That move triggered small protests later from two non-Muslim non-government organizations -- Katagender and Food-not-Bombs.
"I'm warning them and will take stern action as it involves national security," Inspector-General of Police Musa Hassan told reporters on Thursday, according to the state-run Bernama news agency.
Malaysia frowns on oral and gay sex, describing them as against the order of nature. Under civil law, offenders -- male and female -- can be jailed for up to 20 years, caned or fined.
As well as women in trousers, the Fatwa Council is considering barring Muslims from practicing yoga if it includes any Hindu "religious elements" during the exercise.
Islam is the official religion of Malaysia, where more than 60 percent of the population of 27 million are Muslim Malays.