Labor activist Davood Razavi told RFE/RL’s Radio Farda that some 23 protesters were detained.
He said the crackdown demonstrates the lack of tolerance of the Iranian government for even a small form of dissent.
“The drivers wanted to distribute flowers and cookies,” said Razavi in a telephone interview from Tehran.
Ebrahim Madadi, a senior member of the Union of the Workers of Tehran and Suburbs Bus Company, is among those detained.
He was reportedly beaten up and transferred to an unknown location.
