The mudslide occurred in Joumol, a village in Manipur state close to India's border with Myanmar, said police officer Herojit Singh.
Police reinforcements were finding it difficult to reach the area which has been cut off by road because of heavy rains over the past three days, Singh said.
He said that the rescuers would use helicopters to land in the area on Sunday after day-break.
T.S. Warngam, a vice president of the United Naga Council, a civil society organization, said that 20 villagers were feared to have been swept away by the landslide and that one villager was rescued by other residents of the area.
The village is 160 kilometers (100 miles) southwest of Imphal, the Manipur state capital.
Landslides are common in India during the monsoon season, which stretches from June through September.