Nirupam had announced that he would take out a morcha to Raj's residence in Dadar, in the wake of his anti-North Indian statements and incidents of violence in the past two days.
Nirupam, along with a few Congress workers, had assembled at Ganesh Chowk in Dadar, but police detained them before they could proceed to Raj's residence, Deputy Commissioner of Police, Zone 5, D M Phadtare told PTI.
Meanwhile, Maharashtra Navnirman Sena's spokesperson Shishir Shinde was also detained by the police on Tuesday, party sources said.
The police, however, refused to confirm the report. The city has been tense for the last two days, following MNS chief Raj Thackeray's anti-North Indian remarks, and clashes between MNS and Samajwadi Party.
Image: Congress MP Sanjay Nirupam being detained by Mumbai cops.
Photograph: Arun Patil