Users in Kashmir are being kicked off WhatsApp because of inactivity, the BBC has learned.
It is a side-effect of the four-month internet blackout, imposed by the Indian government after the region was stripped of its autonomy in August.
Facebook, which owns the WhatsApp messaging service, said users would need to be re-added to groups "upon regaining access to the internet".
India has 400 million WhatsApp users, making the country its biggest market.
In a statement, a WhatsApp spokesperson told the BBC it "cares deeply about providing users everywhere with the ability to privately communicate with their friends and loved ones".
But it added: "To maintain security and limit data retention, WhatsApp accounts generally expire after 120 days of inactivity.
"When that happens, those accounts automatically exit all their WhatsApp groups. People will need to be re-added to groups upon regaining access to the internet and joining WhatsApp again."
In August, the Indian government revoked part of the constitution that gave Indian-administered Kashmir special status. The region was stripped of its autonomy and split into two federally-run territories, with most of the state's political leaders and workers incarcerated.
Justifying the internet blackout, India's Foreign Minister Subrahmanyam Jaishankar said social media and the internet had been used to radicalise people.