India's Supreme Court on Friday refused to consider a bail plea from a left-wing student leader whose arrest for sedition triggered demonstrations in universities across the country against Prime Minister Narendra Modi's ruling nationalist group.

Rivals said the government was trying to crush dissent after it ordered police to detain Kanhaiya Kumar, the head of the Jawaharlal Nehru University students union, for commemorating the anniversary of the execution of a Kashmiri separatist.

India's top court suggested Kumar, 28, approach the lower Delhi high court for bail, saying it didn't have to intervene in the case and that lower courts were qualified to handle a bail application.

Kumar had sought the Supreme Court's intervention after a previous hearing in a lower court descended into chaos as lawyers chanting nationalist slogans barged into the compound and threw stones at reporters in a case that has become politically charged.

"It was a life-threatening situation," one of Kumar's lawyer Vrinda Grover said, adding it was not safe for the defence team to go anywhere except the top court to seek bail.

A lawyer for Delhi police, which has framed the case against Kumar, said police are duty-bound to provide security at the Delhi high court when the bail application comes up.

The case against Kumar is under the colonial-era sedition law and has fuelled fears that Modi's Bharatiya Janata Party is creating a climate of fear in the country and is promoting a fiercely nationalist agenda aimed at the minority groups.

But the government said the right to speech wasn't unfettered and Home Minister Rajnath Singh put out a Twitter post that those who shouted "anti-India" slogans and challenge the integrity of the country will not be spared.

Kumar and his colleagues were marking the anniversary of the hanging of Afzal Guru, who was convicted of an attack on Indian parliament in 2001.

The attack which India said was masterminded by Pakistan-based militant groups nearly led to war between the nuclear rivals. Guru was convicted for providing logistics to the militants and hanged in 2013.

Human rights and political groups in Kashmir said Guru did not get a fair trial and that the evidence against him was, at best, circumstantial.