The landslide hit the village of Laptap in Pamumpare district, about 40 km (25 miles) south of the state capital Itanagar.
"According to preliminary reports, a hill caved in on a human settlement area trapping about two dozen-odd villagers. Locals have retrieved 16 bodies from the area and about six more people are reported to be missing," Nabam Tuki, a local lawmaker, told Reuters by telephone.
"All roads leading to the village are cut off as there are heavy landslides. Medical teams are having a tough time reaching the village.
"We suspect the death toll would mount as no rescue effort is possible now with the weather conditions very bad," Tuki said.
In adjoining Assam, three people died in floods and landslides on Tuesday, taking the death toll in the state to 33 in the past 15 days.
Over 1.2 million people have been affected by floods in over 2,000 villages in the state, the Assam State Disaster Management Authority said in a bulletin.
The floodwaters have swamped over 100,000 hectares of agricultural land, damaging standing crops, it said.
Indian villagers look on during a rescue operation at the site of a landslide in Laptap village in the Papum Pare district of the state of Arunachal Pradesh.
Sixteen people died and six more were missing after a mudslide triggered by heavy rains tore through a village in India's mountainous northeastern state of Arunachal Pradesh on Tuesday, officials said.
