Indian Muslims say they do not want the gunmen killed by the security forces during the attacks in Mumbai to be buried in Muslim graveyards.
Community leaders believe the militants cannot be called Muslims because they went against the teachings of Islam and killed innocent civilians.
One leader said the militants had "defamed" the religion.
Nine militants died when they stormed targets in India's financial capital, killing at least 172 people.
In what is perhaps their first openly defiant act against "Islamic terrorism", Muslims in India have decided they will not allow the militants to be buried in Muslim graveyards anywhere in the country.
They said that they could not believe that the assailants, who they said had "killed innocent civilians unprovoked", were true followers of Islam.
Ibrahim Tai, the president of the Indian Muslim Council, which looks after the social and religious affairs of the Muslim community in India, said that they had "defamed" his religion.
"They are not Muslims as they have not followed our religion which teaches us to live in peace.
"If the government does not respect our demands we will take up extreme steps. We do not want the bodies of people who have committed an act of terrorism to be buried in our cemeteries.
"These terrorists are a black spot on our religion, we will very sternly protest the burial of these terrorists in our cemetery," he said.
Other Muslim groups have written to their local assembly representatives to say that if the authorities force the militants to be buried in a Muslim graveyard, they too will come out on the streets in protest.
The council move found some support in Mumbai.
One Muslim housewife, Ruksana Sayeed, said: "We Muslims do not even kill an ant, our religion does not teach all this, we are against all these terrorists and I completely agree with the Muslim Council's argument."
However, Naseem Ahmed, a Muslim worker in the city, said the council was wrong.
"They are Muslims and they can be buried even if they have done something wrong. Our religion does not say that those who have done evil can't be buried in a cemetery," he said.
The gunmen held dozens of people hostage in two luxury hotels and a Jewish centre for over 60 hours before they were killed by commandos.
India is believed to have the world's largest Muslim population after Indonesia.