Number missing in Tibet after Nepal mudslide tops 550; China flags upstream risk

About 558 people are now missing after a huge mud-and-rock collapse on the Tibet–Nepal border, including roughly 260 foreign nationals.
The flash flood swept away homes, roads and power projects in Nepal; nearby Tibetan villages have been evacuated and a few people rescued.
Authorities warn a dammed lake upstream could cause more danger, and have sent rescue teams and stepped up monitoring.