Hundreds of protestors began their march against the amended Citizenship Act on Thursday across India.
Historian Ramachandra Guha was detained on Thursday in Bengaluru. The 61-year old was participating in the protest near the Town Hall.
Guha told Indian TV channel NDTV that he has been detained by police for holding a poster of Gandhi and speaking about the constitution to the press.
Big rallies are expected across India on Thursday as the tumultuous and angry reaction builds against a citizenship law seen as discriminatory against Muslims.
Indian Prime Minister Narendra Modi's move to drive the law through parliament last week has ignited nationwide protests that have often turned violent, with six people killed.
The law gives migrants fleeing persecution from neighbouring Afghanistan, Pakistan and Bangladesh an easier path to citizenship, except that Muslims are excluded.
During the past week of unrest, hundreds of people have been arrested, authorities have cut the internet in some flashpoint areas and banned large gatherings in others.