Police registered a case against three PETA activists under section 295 A (outraging religious feelings), Inspector General of Police Yogesh Choudhary said.
As the PETA activists were manhandled, police intervened to protect them and took them to the police station, he said.
PETA said in a statement that "just in time for Bakrid" a lady activist wearing a burqa made of lettuce leaves and vegetables and others were promoting animal- and Earth-friendly vegan diet through a peaceful awareness event near Taj-ul Masjid.
Poorva Joshipura, PETA India CEO, said, "PETA organises peaceful animal protection awareness programs for Christmas, Easter, Diwali, Janmashtami and other holidays, as well as Eid" and "it is shameful that in working to stop violence, our volunteers were made to suffer violence".