Groups of students, journalists and teachers gathered for protests in the Indian capital Tuesday after a student union leader's arrest and subsequent violence by Hindu nationalists.

The uproar has once again sparked allegations of intolerance by Prime Minister Narendra Modi's government and his Hindu nationalist Bharatiya Janata Party, with critics accusing them of cracking down on political dissent in the name of patriotism.

Police cordons blocked right-wing Hindu organizations that support the BJP from entering the campus of Jawaharlal Nehru University on Tuesday, where thousands of students have been protesting for days.

Police also arrested Delhi University lecturer S.A.R. Geelani before dawn. Both he and student leader Kanhaiya Kumar are accused of sedition for participating in events where slogans against India were shouted along with criticism against the 2013 secret hanging of a Kashmiri separatist convicted of attacking Parliament.

Few JNU students attended classes in New Delhi on Monday amid a university call to strike. Later, mobs of lawyers and BJP supporters attacked students outside the courthouse where Kumar was to appear.

The BJP supporters called the reporters and students anti-nationals and demanded they leave India and go to Pakistan, the country's archrival and Muslim-majority neighbor. The protests, meanwhile, brought New Delhi traffic to a standstill for several hours Monday.

India's Human Resource Minister Smriti Irani told reporters that "the nation can never tolerate an insult to Mother India." The home minister, Rajnath Singh, has said that anyone shouting anti-India slogans "will not be tolerated or spared," according to his Twitter account.

Singh accused Pakistani Hafiz Saeed of orchestrating the anti-India slogans, which the founder of the Lashkar-e-Taiba group dismissed in a YouTube video posted Monday.

"The Indian minister is misleading his own people and the world" in trying to blame Pakistan for its problems, says Saeed, who is wanted in India and the United States for his alleged role in the 2009 attacks in Mumbai.

An editorial Tuesday in The Indian Express newspaper said the home minister's "invoking Hafiz Saeed to corner students is divisive and dangerous."

Protests against the 2013 hanging of separatist Afzal Guru have also sparked regular protests in the disputed Himalayan territory of Kashmir, where most people believe he was not given a fair trial.

On Tuesday, the students were joined by JNU teachers for their demonstration inside the gated, university campus to demand Kumar's release. Academics at foreign universities, including Harvard, Cambridge and Yale, also extended support.

"As teachers, students, and scholars across the world, we are watching with extreme concern the situation unfolding at JNU and refuse to remain silent as our colleagues (students, staff, and faculty) resist the illegal detention and autocratic suspension of students," said a statement posted on a blog run by academics and signed by 455 scholars, many of whom are of JNU alumni of Indian descent.

Most university classes were still suspended, according to PhD science student Pamchui, who goes by one name.

"I am feeling safer now, as there is security outside the campus," she said by telephone from inside the campus.

Journalists also marched through central New Delhi on Tuesday, after several were reportedly attacked by mobs while trying to cover Monday's protests. Journalist unions demanded better protection for reporters in the field, and accused police of standing by during the attacks.

Critics have called the government's reaction to the protests at a university known for politically active students as extreme, and blame a rising climate of intolerance for dissenting views under Prime Minister Narendra Modi and his party, which came to power in 2014.

Scores of artists, scientists and historians have returned government awards to protest against what they view as the government's silence or complicity in creating a climate where criticism is viewed as unpatriotic.