Flash floods that swept through parts of Nepal on Wednesday triggered alerts in the neighbouring Indian states of Uttar Pradesh and Bihar, with authorities closely monitoring linked river systems and preparing for possible water level rises, according to a PTI report.

The concern is tied to the connection between Nepal's Narayani river and India's Gandak river, which form a single transboundary river system. As the flood situation worsened in Nepal, Bihar authorities opened all 36 gates of the Gandak Barrage at Valmikinagar as a precautionary measure to manage increased flow.

In Uttar Pradesh, Chief Minister Yogi Adityanath directed officials in the eastern districts of Maharajganj and Kushinagar, located along the river's course, to remain on heightened alert.

Authorities in both states are monitoring the rivers closely as water levels from the Nepal flooding move downstream.