Violence erupted at the Tata Motors plant site in Singur on Sunday when police fired rubber bullets and teargas at Krishi Jami Rakhsha Committee activists when they hurled bombs and bricks in a bid to enter the area.
Members of a Trinamool Congress-backed body torched a police watch-tower and uprooted fence posts at the Tata Motors' small car project site.
Around 100 people of the committee entered the fenced off area at Bajemelia in Singur bloc early on Wednesday morning to uproot the posts.
Patkar, who was accompanied by members of Association for Protection of Democratic Righs, SUCI and women rights activist Anuradha Talwar, went around the area in a large group as police personnel looked on.
The demonstration came in the wake of the High Court's observation on February 23 that the state government's process for acquiring land at Singur for the project prima facie appeared to be illegal.