At least 18 people have died and hundreds are missing after a flash flood struck Nepal’s Rasuwa district north of Kathmandu early on Wednesday, BBC reported citing Nepalese police.

The death toll was confirmed by 15:45 local time, according to a police statement. One body was found in Rasuwa, seven in Nuwakot, six in Dhading and four in Gorkha.

The affected route is a key gateway to Langtang National Park trekking and Gosainkunda, a holy lake on the mountains, where people pay homage during the Rakshabandhan festival on Friday.

About 400 tourists, including 291 foreign nationals, were unaccounted for, Hikmat Singh Ayer, acting chief executive of Nepal Tourism Board, told BBC Nepali. Most were travelling towards Kailash Mansarovar in Tibet.

“The figure is being updated as reports continue to come in from tour operators running Tibet-bound packages for rescues,” Ayer said.

Those missing included more than 100 Indians, 17 Malaysians, 12 Britons, four South Africans and nationals from the United States, Australia and the Netherlands.

Nepal’s foreign minister said early information suggested the flood was caused by an earthquake triggering an avalanche.

The US embassy in Nepal said authorities had reported severe flooding in Rasuwa and issued warnings for communities along the Bhote Koshi, Trishuli and Narayani rivers.

Meanwhile, Chinese state media outlet CCTV reported “major casualties” from a mudslide at a trade hub on the Tibetan side of the shared border.

Chinese President Xi Jinping urged “all-out” search efforts for the missing, as well as stronger monitoring and early warning systems to prevent secondary disasters, according to CCTV.