Activists have called the arrest of Father Stan Swamy by the NIA a "condemnable act" against a "kind" man fighting for the rights of tribals.
The 82-year-old was arrested by the central probe agency on Thursday from his Ranchi (Jharkhand) home for his alleged involvement in inciting a mob to violence in Bhima Koregaon near Pune on January 1, 2018.
"Shocking and condemnable act on the 83-year-old priest who has spent all his life serving the poor," Swaraj India party president Yogendra Yadav said in a tweet.
Activist and lawyer Prashant Bhushan described Father Swamy as a nice person.
"Just got the news that the NIA has forcibly taken octogenarian Father Stan Swamy from his ashram at Ranchi. It would be difficult to imagine a gentler and kinder person."
"It is the sign of the venality of the NIA that they are trying to implicate him under UAPA! (Unlawful Activities Prevention Act)," Bhushan tweeted.
"Like Sudha Bharadwaj, Stan Swamy has spent a lifetime fighting for the rights of Adivasis."
"That is why the Modi regime seeks to suppress and silence them; because for this regime, the profits of mining companies take precedence over the lives and livelihoods of Adivasis," historian Ramchandra Guha said in a tweet.
Activist Harsh Mander too expressed his support for Swamy.
"Father Stan Swamy in his 80s has served India's tribal people selflessly, struggled with them peacefully against injustice. One by one, the state is hounding India's finest sons & daughters. Why is it so frightened of those who speak for the most oppressed? #IStandWithStanSwamy," Mander tweeted.
Journalist and filmmaker Pritish Nandy said it was "very tragic to see an 83-year-old priest fighting for Adivasi rights being arrested in the midst of a raging pandemic."
However, BJP's national secretary and Tripura in-charge Sunil Deodhar endorsed the NIA action.
"It's good that NIA arrested Stan Swamy, a Jharkhand based Jesuit priest and member of banned outfit CPI(Maoist), in Bhima Koregaon case.
"This may further reveal links between the Christian missionaries and Urban Naxals," he said on Twitter.