Tehran police Chief Hossein Sajedinia confirmed the arrests on state TV late Tuesday in a report that blurred images from the video and then showed the six with their backs turned toward the camera.
“They were identified and arrested within six hours,” Sajedinia said.
In the TV broadcast, those arrested said they had been deceived and that the video was not meant to be posted on the Internet.
“They had told us that this video won’t be released anywhere and that it was for our own joy,” one of the women said.
Another detainee said: “They invited us to appear on the video to practice acting.”
It wasn’t immediately clear if the six faced criminal or civil charges, or if they had lawyers.
On the broadcast, Sajedinia warned Iranian young people that police will confront those who challenge Islamic and social norms.
“The youth should try not to be deceived by these people under pretexts such as acting or singing,” he said.
The last time there was a crackdown on music was on Dec. 2, 2013, when Iran’s Morality Police temporarily arrested popular rapper Amir Tataloo, whose songs authorities deem inappropriate. He was released two days later.