Thousands of people from countries around the world are missing after flash flooding devastated the mountainous border region between Nepal and China on Wednesday, killing at least 353 people and leaving more than 1,300 unaccounted for, according to officials and local reports.

Among those missing are at least 47 U.S. citizens, according to the latest figures. Local reports, citing Nepal’s National Emergency Operation Center, said those missing in Nepal included 113 Nepali tourists, 85 security personnel from the army and police, and 162 residents of nearby villages.