A massive landslide caused by heavy rainfall blocked the flow of the Siji river in Arunachal Pradesh’s Lower Siang district on Sunday (June 28, 2026), endangering lives and infrastructure downstream.

District officials said the debris dammed the river at the Siji-Magi Block Point, creating an artificial lake. They said rainfall-induced water accumulation had increased the possibility of the dam giving way and causing a flash flood. The point is a few miles above Likabali town on the State’s border with Assam.

The district authorities have alerted residents of Likabali town and villages along the Siji river, which becomes the Gai river in Assam.

“We have advised people in the downstream areas to remain alert, as there is a possibility of a powerful flash flood without warning if the artificial dam breaks. Such an event could endanger lives, homes, livestock, roads, bridges, and other public infrastructure downstream,” an official said.

People have been advised to stay away from riverbanks, avoid unnecessary movement near the river, evacuate low-lying and flood-prone areas if instructed by the authorities, and be prepared to move to safer locations at short notice. The residents have also been urged to immediately report any sudden rise in the river’s water level, unusual sounds, or signs of the blockage weakening to the nearest administrative or police authority.

Officials in the adjoining Dhemaji district of Assam said the flood had affected four revenue circles — Jonai, Sissiborgaon, Dhemaji, and Gogamukh. The flood has affected 15,483 people across 69 villages in the district.

“A railway bridge across the Simen river has collapsed, an iron bridge has been washed away, and embankment erosion has been reported along critical stretches of the arterial National Highway 52,” a district official said.

Search continues

Meanwhile, rescue workers continued to search for three missing persons, including a minor, who went missing after a flash flood hit a hydropower project colony in Arunachal Pradesh’s Keyi Panyor district on June 24. The bodies of two victims have been recovered.

On the brighter side, Border Roads Organisation personnel restored the Kimin-Potin Road district within 36 hours after torrential rains, flash floods, and landslides caused widespread devastation in Keyi Panyor and Papum Pare districts. The road is a lifeline for five districts at a higher elevation than Keyi Panyor.

The incessant rainfall had triggered multiple landslides and major breaches along a 45-km stretch of the road, washing away sections of the roadway, and burying several areas under mud, boulders, and uprooted trees.

The disruption had completely halted vehicular movement and severed connectivity to several strategic locations, including Potin, Yazali, Yachuli, Joram and Ziro.