India on has expelled a 24-year-old German student on Tuesday after he had joined protests against a new citizenship law, believed to be discriminatory against Muslims. 

In photos circulated by Indian media, student Jakob Lindenthal was shown holding a placard equating the Indian government's practices with those of Nazi Germany. It read: "1933 to 1945 -- we have been there."

Confirming that Lindenthal was told to leave the country, an Indian government official told media that German student -- enrolled in the Indian Institute of Technology in the southern city of Chennai -- had violated student visa conditions.

Students across India have been protesting against the new law granting citizenship to Hindus, Parsis, Sikhs, Buddhists, Jains and Christians -- but not Muslims -- who migrated from Afghanistan, Bangladesh and Pakistan.

Activists have called the law discriminatory, fearing that it was aimed at disenfranchising Indian Muslims. However, Prime Minister Narendra Modi has rejected such claims.

Lindenthal told The Indian Express, an English language newspaper that he received "oral directions" from the Foreign Regional Registration Office (FRRO) to leave India.

"I felt the gratefulness of many people in the protest for the solidarity from a foreigner. So, I wanted to give them at least my moral support again after having attended the protest march on the campus of IIT Madras," Lindenthal told German broadcaster Deutsche Welle.

"After the Nazi era, many people claimed not to have known anything about genocides or atrocities or stated that they were only passive," he said.

"Therefore, I see it as a duty to learn from these lessons and not only watch when things happen that one believes to be the stepping stones to a possibly very dangerous development," he told the Indian newspaper before leaving for Germany.

The student said he was summoned to the FRRO office where he was giving marching orders.

“We discussed the demonstration culture. There were three officers including one who asked me all questions. All of them were unnamed. Towards the end of the conversation, they said I may have to leave the country immediately for violating my student visa rules,” he told Indian Express.

Muslim student prevented to attend convocation

Meanwhile, a Muslim student at Pondicherry University has alleged that she was not allowed to attend her convocation ceremony.

Rabeeha Abdurehim, a gold medal winner, alleged that she was prevented from attending the convocation ceremony on Monday at her university, where President Ram Nath Kovind was the chief guest.

Rabeeha, who had done her Masters course in Mass Communication, had refused to accept the gold medal from the President, to show solidarity with students protesting against the new citizenship law.

“The student claimed she was asked by a senior police officer to leave the auditorium before the commencement of the convocation,” said news agency Press Trust of India (PTI). The university administration has refused to comment on her allegations.

In West Bengal, Governor Jagdeep Dhankar was shown black flags by students at the Jadavpur University on Tuesday. He was greeted with placards that read "BJP [Bharatiya Janata Party] activist Mr Jagdeep Dhankar, go back", said PTI.

According to the news agency, the Governor who was invited for the convocation ceremony termed the whole incident “unpleasant and worrisome”.