US, Aug. 27 -- A catastrophic flash flood in Nepal has left hundreds of people dead or unaccounted for, including a large number of international visitors, turning the disaster into a global tourism emergency.

The flooding struck the Bhote Koshi River corridor near Nepal's border with Tibet on August 26, sending a massive surge of water and debris through communities, roads, bridges and areas used by tourists traveling through the Himalayan region. Search, rescue and evacuation operations remain underway.

The number of people reported missing has changed rapidly as authorities, tourism companies and families establish contact with travelers. The Nepal Tourism Board reported Thursday that 644 Nepali and foreign travelers were listed as ...