RIYADH, Saudi Arabia — An outspoken Saudi blogger is being held for “purposes of interrogation,” the Saudi Interior Ministry confirmed Tuesday.

Gen. Mansour al-Turki, an Interior Ministry spokesman reached by telephone, said the blogger, Fouad al-Farhan, was “being questioned about specific violations of nonsecurity laws.” Mr. Farhan’s blog, which discusses social issues, had become one of the most widely read in Saudi Arabia.

Ahmad al-Omran, a blogger and a friend of Mr. Farhan, said that Mr. Farhan had been the first Saudi blogger to be detained by state security. The arrest created widespread anxiety among other Saudi bloggers and advocates, he said.

“An incident like this has its effect,” Mr. Omran said by telephone. “It’s intimidating to think you might be arrested for something on your blog. On the other hand, this means that these voices on the blogosphere are being heard. But it’s really sad that a blogger who is writing about important issues out in the open would get arrested, while there are extremists who call for violence and hate, and the government is not doing much.”

Mr. Omran said Mr. Farhan was one of the first Saudi bloggers to post items in Arabic and to use his real name. At the top of Mr. Farhan’s blog is a call in Arabic for “freedom, dignity, justice, equality, public participation and the other lost Islamic values.”