Catastrophic flash flooding has hit China and Nepal, with at least 95 people confirmed killed. The toll is likely to rise. Hundreds of tourists, including foreign nationals, are missing.The small Himalayan nation has been badly hit. Dramatic footage shows a torrent of water hitting the Nepal-China border and villages lie submerged .Emergency personnel using helicopters have been rescuing stranded people from rooftops.Are you or someone you know affected? Email iwitness@rnz.co.nzState media in China reports some casualties and more than 250 people missing. A mudslide hit China's Gyirong port, with Chinese leader Xi Jinping urging "all-out" search efforts. The quick response of China's leadership is another sign of the severity of the disaster.Nepal's foreign minister said an earthquake triggered a large landslide, which in turn blocked the Bhote Koshi river, sending a torrent of water downstream from China to Nepal.A helicopter pilot who witnessed Wednesday's deadly flash flood from the air near the China-Nepal border said he estimated the waves to be "as high as five to six meters.""We could see water waves as high as five to six meters … We started circling around villages there and could see big trees along with a few vehicles being swept away," Aman Budathoki said. "It was a very scary situation. We even tried to chase the flood for a while just to assess the damage unfolding."He concluded by saying he had never witnessed the power of nature "unfold like this."While avalanches can be caused by a number of factors, climate change often plays a role, scientists say. Nepal, in the rapidly-warming Himalayan region, is home to thousands of glaciers which are melting and destabilizing as temperatures rise.A spokesperson for the Ministry of Foreign Affairs and Trade said the New Zealand High Commission in New Delhi is in contact with authorities in Nepal to seek information about New Zealanders who may have been affected."All New Zealanders in Nepal should follow the advice of local authorities at all times, including any evacuation orders. New Zealanders in Nepal should also let their family and friends know that they are safe when they are able to."They said any New Zealanders requiring consular assistance can call the 24/7 consular emergency line on +64 99 20 20 20.-CNN with additional reporting from RNZ