At least 639 people remain stuck in several devastated hydropower stations that have become the focus of rescue efforts, the country's disaster management authority said on Tuesday. Nepalese authorities say 4,000 people remain unaccounted for as rescue teams with search dogs comb through mud, rocks and debris. Key points and original sources are listed below.

• At least 639 people remain stuck in several devastated hydropower stations that have become the focus of rescue efforts, the country's disaster management authority said on Tuesday.S1

• Nepalese authorities say 4,000 people remain unaccounted for as rescue teams with search dogs comb through mud, rocks and debris.S2

• A total of 3,916 people were said to be missing throughout Nepal, the government said.S3

• By Gopal Sharma, Sahana Bajracharya, Liz Lee and Ethan Wang KATHMANDU/BEIJING, Sept 1 (Reuters) - Nepali rescuers built temporary bridges to reach remote areas and dug through the ruins of hydropowerS4