RPI leader and MP Ramdas Athawale was detained by city police on his arrival at the airport in Nagpur on Monday, police said.
Athawale was among five Dalit leaders, who alongwith CPI(M) politburo member Brinda Karat, were banned from entering the city to participate in a rally to protest the Khairlanji Dalit killings.
Dalit leaders, including Prakash Ambedkar, Jogendra Kawade, Sulekha Kumbhare and Rajendra Gavai were scheduled to take part in the protest rally.
However, as police denied permission to Dalit organisations for the rally in view of the commencement of the winter session of Maharashtra Legislature on Monday and the recent incidents of violence in parts of the state, the Dalit outfits are likely to organise a peace meeting.
Meanwhile, police also appealed to people not to assemble at 'Deekshabhoomi' where late Dr Babasaheb Ambedkar had embraced Buddhism in 1956.