A group of Indian Americans sang the traditional civil rights anthem “We Shall Overcome” — alternating the stanzas between English and Hindi — during a recent protest in Harvard Square in Cambridge.

“Oh deep in my heart, I do believe,

“We shall be free someday,” sang the group of about  40 who were holding placards and standing in a circle in the square on May 13.

They gathered to call for the release of Dr. Binayak Sen on the one-year anniversary of his imprisonment in India.

Dr. Sen, a pediatrician, public health specialist and the vice president of the People’s Union for Civil Liberties, was allegedly arrested on false charges of inciting rebellion against the Indian government, according to the brochures distributed at the protest. His arrest is likely the result of his opposition to the private armed militia that the government is using to combat the “Maoist insurgency” in India, the brochures said. 

Arlington resident and protest organizer Somnath Mukherji, who directed the demonstrators in the square while balancing his nine-month-old daughter on his arm, said Dr. Sen was detained under the “Chhattisgarh Special Public Security Act,” a new law that allows the Indian government to imprison people for as long as seven years without trial. The charges against the doctor, who according to Mukherji did nothing more than try to provide medical care to some insurgents and ensure that the prisoners had access to legal aid, “are very grave and could lead to the death sentence.”

“Injustice anywhere is a threat to justice everywhere,” Mukherji said, quoting the American civil rights leader Dr. Martin Luther King, Jr.

A Harvard physics student from India, Suvrat Raju, 26, said the Maoist insurgency in Chhattisgarh is about caste oppression and the control of local resources, especially land rights. He said that although he does not approve of armed rebellion, jailing people and using a private militia are not good ways to address the situation.

“It affects all of us in India,” said Raju, who is scheduled to return home in June. “The Indian government likes to say that it’s a democracy, but it clearly doesn’t uphold democratic values on the ground.”

One of Dr. Sen’s friends who attended medical school with him in India also protested in Harvard Square. Honorine Ward, who teaches a course on infectious diseases at Tufts Medical School, said Sen is “a very good personal friend” whom she’s known for 30 years.

Ward said Dr. Sen gave up a prestigious career in pediatrics to go to Chhattisgarh and set up clinics for rural poor and tribal people. After being put in prison, he was “thrown into solitary confinement for two weeks” for trying to provide some medical help to the other prisoners, Ward said.

The protesters held candles and hand-written signs that said “Repeal the Chhattisgarh Special Public Security Act” and “Stop Oppressing Descent.” Similar protests were held in San Francisco, New York and London, Mukherji said.