Tangkhul Naga Long (TNL), an NGO in Manipur, has banned the sale of beef in any form in the Ukhrul district of the state.
The NGO decided to prohibit the sale of beef following the deaths of several cows and buffaloes in Ukhrul district.
No slaughter is allowed within the district, a notification by TNL said.
The notification said that a mysterious disease has claimed dozens of cows and buffaloes on the northern side of the district which borders Myanmar.
The district authorities have not taken any steps to identify the disease and educate the tribals in the interior areas, activists alleged.
It is feared that many people might have become susceptible to some serious diseases.
There is a free sale of beef in other parts of the State.
Police said that the meat sellers do not possess a mandatory license for opening meat shops.