Search and rescue teams continued operations for a second straight day on Thursday to locate four people still missing after devastating flash floods ripped through Arunachal Pradesh's Keyi Panyor district, leaving a trail of destruction and prompting flood warnings downstream in Assam.

The disaster struck the NEEPCO project colony near Poosa under the Yazali circle after incessant rainfall triggered flash floods and severe waterlogging in the area. Five people were initially reported missing.

Rescuers recovered the body of one of the missing persons, Nirmala Gupta (35), a teacher at Vivekananda Kendra Vidyalaya (VKV), on Wednesday afternoon. Four others — Elesh Marak (13), Balari Marak (30), Tao Anjina (46) and Sourav Kumar (48) — remain untraced.

At least 20 people sustained injuries in the calamity, including three who are in critical condition and undergoing treatment at a government hospital.

Officials said continuous heavy rainfall caused an under-construction retaining wall to collapse, leading to flooding in low-lying residential areas around the colony. Nearly 20 houses and residential units were damaged, while several goods-laden vehicles were either swept away or severely damaged by the floodwaters.

The state-owned North Eastern Electric Power Corporation (NEEPCO) has begun releasing water from the Ranganadi Dam as a precautionary measure amid rising inflows. Power generation at the hydropower project has been temporarily suspended.

The floods are part of a broader weather emergency unfolding across Arunachal Pradesh, where days of relentless rainfall have triggered landslides, flash floods and extensive damage to infrastructure in several districts.

Authorities have advised residents living along riverbanks and in vulnerable areas to remain alert and avoid unnecessary travel as the threat of further flooding persists.

Expressing grief over the tragedy, Union Minister Kiren Rijiju said he was deeply saddened by the loss of lives and destruction caused by the floods and landslides in Keyi Panyor district.

"Rescue, relief and restoration efforts are underway, and every possible assistance is being extended to those affected. We stand firmly with every affected family in this difficult hour," Rijiju said in a post on X.

Meanwhile, neighbouring Assam has been placed on high alert amid fears of a significant downstream impact from the heavy rainfall and flash floods in Arunachal Pradesh.

State authorities warned that rising river discharge and increased flow velocity could sharply raise water levels in the Brahmaputra and its tributaries. The first impact is expected in Dhemaji, Lakhimpur, Biswanath and Sonitpur districts before floodwaters move further downstream towards western Assam, including Dhubri, over the next one to two days.

The Assam government said the situation is being monitored at the highest level as authorities brace for a possible flood wave originating from the upper catchment areas of Arunachal Pradesh.

With IANS inputs