Nepal may need $4 billion to $5 billion to rebuild after devastating floods triggered by a glacier collapse in the Himalayan region, Finance Minister Swarnim Wagle told Reuters on Saturday. The collapse occurred last Wednesday, sending rocks, ice, mud and debris downstream and causing severe flooding in Nepal and China’s Tibet. Damage assessments are still under way, and Wagle said the estimate remains preliminary.

More than 600 people have been killed across the two countries, while over 2,000 remain missing. Strong flood currents damaged several towns and settlements near the border, washing away bridges and roads. Important hydropower plants were also affected, adding to the scale of the disaster.

Wagle said the reconstruction requirement could be lower than the amount needed after Nepal’s 2015 earthquake, when about $9 billion was spent on rebuilding. The floods have damaged hydropower projects responsible for more than 12 percent of Nepal’s total electricity-generation capacity. Securing reconstruction funds, restoring infrastructure, normalizing electricity production and reviving economic activity are identified as major challenges.