Sudden floods triggered by heavy rains have killed more than 200 people across parts of Pakistan, India-administered Kashmir and Nepal, authorities have said, as scores of people remain missing.

In Pakistan, a helicopter carrying relief supplies to the flood-hit northwestern Bajaur region crashed due to bad weather, killing all five people on board, including two pilots, a government statement said.

Dozens of people are missing in both countries, while rescuers in Pakistan have evacuated 1,300 tourists trapped by flash flooding and landslides. Meanwhile, a helicopter carrying relief supplies has crashed in bad weather.