A strong 6.1-magnitude earthquake struck Arunachal Pradesh early Wednesday, the US Geological Survey said.
The epicenter of the shallow earthquake was about 40 kilometres (25 miles) southeast of Along, and 180 kilometres southwest of the state capital Itanagar.
It struck at 1:45 am.
Arunachal Pradesh is the least densely populated state, but is still home to more than 1.2 million people, according to the state government's website.
China's official state news agency Xinhua said the earthquake was felt in Tibet, which neighbors the state.
New Delhi and Beijing for decades have disputed control of Arunachal Pradesh -- a dispute that remains unresolved.
Arunachal Pradesh also borders Myanmar and Bhutan.
USGS estimated there was a "low likelihood" of casualties and damage from the earthquake.