Police in India have registered a sedition case against Amnesty India after some people allegedly raised "anti-India" slogans at its event.
The rights group said its event in Bangalore on Saturday aimed "to seek justice for human rights violations" in Indian-administered Kashmir.
But a right-wing student group said the event was "anti-national" and filed a complaint on Monday.
In February, two students were arrested in Delhi on sedition charges.
"A case has been registered [against Amnesty] after the compliant [by the student group ABVP]," senior police officer Charan Reddy told BBC Hindi.
"We haven't named any individual involved in the event. But action will be taken after we finish our investigation," he added.
Aakar Patel, executive director of Amnesty International India, has criticised the ABVP's complaint.
"Merely organising an event to defend constitutional values is now being branded 'anti-India' and criminalised," he said.
"The police were invited and present at the event. The filing of a complaint against us now, and the registration of a case of sedition, shows a lack of belief in fundamental rights and freedoms in India."
Reports said some Kashmiri students started raising "anti-India" slogans after a participant praised the Indian army.
Around 60 people have been killed and more than 5,000 injured in Indian-administered Kashmir in recent weeks as protesters have repeatedly clashed with security forces.
The recent upsurge in violence has been triggered by the killing of militant leader Burhan Wani.
Disputed Kashmir is claimed in its entirety by both India and Pakistan and has been a flashpoint for more than 60 years, sparking two wars between the countries.
Within the Muslim-majority territory, some militant groups have taken up arms to fight for independence from Indian rule or a merger with Pakistan.