Activists’ arrest over alleged caste incitement also draws condemnation from rights groups and opposition parties.

India‘s Supreme Court has asked the Indian government to explain the arrests of five prominent activists in connection with caste violence that took place earlier this year.

The high-profile arrests triggered outrage and protests across India on Wednesday.

“Dissent is the safety valve of democracy. If you don’t allow the safety valve, the pressure cooker will burst,” Justice Dhananjaya Yeshwant Chandrachud, who is among the three judges hearing the case at the Supreme Court, observed.

The arrested human rights activists received a reprieve from the top court, which directed that they be held under house arrest instead of police custody.

On Tuesday, searches were carried out at the homes of poet Varavara Rao in the southern city of Hyderabad; activists Vernon Gonsalves and Arun Ferreira in Maharashtra, trade union campaigner and law professor Sudha Bhardwaj in Faridabad; and civil liberties activist Gautam Navalakha in New Delhi. Subsequently these five were arrested.

Police said the activists had spurred Dalits in the face of a pride event at Bhima Koregaon in January that spilled over into weeks of violence and protests across Maharashtra state.

Dalits, at the lowest rung of the Hindu caste system, have suffered thousands of years of exclusion and extreme poverty.

On Wednesday, protests were held across India by 37 civil rights groups and enraged Indians protested on social media even as activists warned of a further crackdown on those defending human rights in the country.

The police are also probing the alleged connection of those arrested to Maoist rebels who have been involved in an armed struggle for decades against Indian security forces.

Maoist rebels, also known as Naxals, claim to fight across states in central and eastern India, for the rights of tribals, poor farmers and landless labourers.

On Twitter, Indians shared their outrage and trended #MeTooUrbanNaxal.

If @Sudhabharadwaj is a naxal, I am a naxal too. Arrest me. #MetooUrbanNaxal — nikhil wagle (@waglenikhil) August 29, 2018

If quelling and intimidating the voices of dissent is your idea of democracy , then saying on your face, Mr Prime Minister @narendramodi , — Me Too Urban Naxal #MeTooUrbanNaxal @free_thinker — Anurag Tripathi (@anurag999) August 29, 2018

When human rights violators are awarded plum positions and human right activists are killed/humiliated/jailed. #MeTooUrbanNaxal — Brenna Ribeiro (@BrennaRibeiro03) August 29, 2018

Dissent is patriotic #MeTooUrbanNaxal — Rajesh Sanyal (@sanyalrajesh) August 29, 2018

The police had also arrested five Dalit activists in June this year in connection with the same case.

The government has been trying to silence those who are defending the defenceless, said Supreme Court lawyer Prashant Bhushan, who challenged the arrests at the top court on Wednesday.

“This is an outright attempt to intimidate human rights activists, dissenters and silence those who are opposed to the fascist policies of this government,” Bhushan told Al Jazeera.

“What those arrested have in common, they are our finest rights activists speaking out against the government. They are standing up for the rights of the poor and the marginalised in this country,” he added.

The Supreme Court will resume hearing the case on September 6.

Joint Commissioner of Pune Police Shivaji Bodkhe confirmed the arrests but refused to answer questions from Al Jazeera.

India’s National Human Rights Commission has sent a notice to the government of Maharashtra asking them to explain the arrests while Amnesty International has called it a “crackdown on human rights activists”.

The ruling Bharatiya Janata party has defended the crackdown.

“Those arrested are violent people who are conspiring against Indian society. Maoism is a banned ideology, so what do you expect?” BJP leader and Member of Parliament, Rakesh Sinha told Al Jazeera.

“India is neither Saudi Arabia nor China. The doors of the judiciary are open to them if they think they are innocent. Let there be a free and fair trial,” he added.

But the arrests have brought back into the spotlight the debate about what some called the shrinking space for dissent in India under the government of Hindu nationalist Narendra Modi.

Gauri Lankesh, journalist and a strident critic of the current ruling party and its ideology, was killed last year, while a left-wing student leader Umar Khalid survived an assassination attempt this month.

Critics also pointed to the several arrests of Dalit activists including leaders like Chandrashekhar Azad who has been imprisoned under India’s draconian National Security Act since last year as examples of the right-wing government’s clampdown on tolerance and freedom of expression.