India’s Home Minister Rajnath Singh said in a tweet that his government is “not violating any international law” if it deports Rohingya refugees “as we are not a signatory to the 1951 Refugee Convention”.

Hold on. If India had not signed the Convention Against Torture, would Indian authorities have carte blanche to torture and ill-treat anyone in custody? Of course not. India knows full well that certain principles of international law are considered customary international law – they are unlawful because states have long prohibited the practice as a matter of law. It doesn’t matter whether or not the country has ratified a treaty on the subject. And, if it is wrong to torture or persecute someone, forcing someone to return to a place where they face these abuses is also unacceptable.

The home minister correctly cites the 1951 Refugee Convention as a source of law for the principle of “nonrefoulement”, which prohibits the return of refugees “in any manner whatsoever” to places where their lives or freedom would be threatened. He could also have cited the 1984 Convention Against Torture, which prohibits the return of anyone to another country where there are substantial risks of torture. There are also other regional conventions and declarations that endorse the principle, such as the 1969 OAU Refugee Convention, the 1969 American Convention on Human Rights, and the 1966 Bangkok Principles on Status and Treatment of Refugees.

But that’s not the end of the story.

Certain rules of customary international law are so important that no government can violate them even if a treaty existed that would allow them to do so. The prohibitions on torture and slavery are such “peremptory norms”. As early as 1982, the executive committee of the United Nations High Commissioner for Refugees, which is comprised of 101 countries including India, affirmed that the principle of nonrefoulement was “progressively acquiring the character of a peremptory rule of international law”.

The Indian government says it is worried about the entry of refugees with links to Rohingya militants. If that’s the case, they should produce evidence and prosecute individual suspects. While a Rohingya militant group attacked security posts in Burma, it is the campaign of ethnic cleansing by the Burmese military that has caused the Rohingya to flee, most to Bangladesh but some to India.

When your neighbour flees his burning house, you are not at liberty to push him back into the flames because you consider him a trespasser. The Rohingya are literally fleeing their burning homes. The obligation not to push them back stems less from a signature on a piece of paper than from the fundamental principles of our shared humanity.

This article first appeared on The Human Rights Watch website.