At least 389 people have died and nearly 1,500, including foreign nationals, remain missing after sudden flooding and landslides in Nepal near the Tibetan border. The disaster struck around 9 a.m. local time on Wednesday, with water, mud and rocks surging through the Lende Khola valley and inundating villages. Authorities fear the casualty and missing-person totals could rise; across the border in Tibet, at least 558 people were reported missing and three dead.

The flooding is preliminarily linked to a glacier collapse in the Bhote Koshi River valley of Nepal’s border district of Rasuwa. The torrent destroyed homes, power towers and other infrastructure, washing away at least 19 bridges and about 40 kilometres of road. More than 500 tourists from several countries are among those missing, including 177 Indians, 100 Chinese and 63 Americans. Nepal’s embassy in Bangladesh said no Bangladeshi citizen had been reported killed, injured or missing.

A new lake formed by the collapse about 40 miles north of Kathmandu holds about 2 million cubic metres of water, with another 3 million cubic metres potentially entering within three days. Nepal has divided rescue, relief and rehabilitation operations into 12 teams, while military personnel use helicopters, drones and search dogs despite blocked roads, high water and deep mud.