Aug. 27 (UPI) — The death toll from a flash flood that tore through Nepal’s mountainous border region near China rose Thursday to 177, with hundreds still missing, according to officials

The devastating flash flood, reportedly triggered by an avalanche, hit north-central Nepal on Wednesday morning, leaving a wide swath of damage and destruction in its wake.

Nepal Police announced the updated death toll, stating the figure was current as 10 a.m. local time, while the National Disaster Risk Reduction and Management Authority said at least 73 people were reported injured as of 11 a.m.

However, both figures are expected to fluctuate as at least 826 people remained unaccounted for, including 578 tourists, the NDRRMA said.

Among the missing were 63 Americans, The Kathmandu Post reported, citing data from the Nepal Tourism Board. The board said 177 Indians, 53 Ukrainians, 33 Britons, 25 Canadians, eight Germans and six Singaporeans and six South Africans were also missing.

Malaysia’s Foreign Ministry said 55 of its nationals were missing, Australian Foreign Minister Penny Wong said 34 Australians were missing and Japanese Prime Minister Sanae Takaichi said five of her citizens were also unaccounted for.

“I am concerned for the well-being of our compatriots, the Nepalese people and all foreign nationals staying there, and I pray earnestly that their irreplaceable lives will be protected,” she said in a statement.

In China, state-run media reported 558 people, including 260 foreign national, were missing due to mudslides in Tibet’s Gyirong County, which borders Nepali. The number of people missing had nearly doubled in 12 hours.

More than 7,450 police officers and soldiers have been deployed to the affected areas in Nepa, conducting at least 37 flights and rescuing 305 people, according to officials.

The Nepali Army said its aircraft evacuated 125 people, including 20 foreign nationals, from the Timure and Mailung areas on Thursday morning.

Its emergency treatment center in Trishuli was treating 64 people who had been injured, the army said.

The Prime Minister’s Office of Nepal said search-and-rescue operations along riverbank and affected areas were intensified on Thursday morning.

According to the U.S. Geological Survey, the flash flood was initially registered as a magnitude 4.4 earthquake that struck at 8:37 a.m. Wednesday, but additional analysis of long-period seismic waves indicated that “the seismic energy was instead generated by a glacial collapse and debris flow.”