Rescue teams have resumed operations along the Nepal-Tibet border after a temporary pause over fears of another glacial flood.

Nepal’s National Disaster Management Authority said 673 bodies had been recovered by Saturday. The number of people missing on the Nepalese side has also risen to 2,496. That figure includes 517 foreigners, who may be tourists or foreign workers.

Chinese authorities reported at least seven deaths in Tibet, with another 554 people still missing.

The Nepalese government has requested specialist assistance from India and China to strengthen its rescue efforts. Specialist teams, including tunnel rescue experts, are expected to arrive later on Saturday.

The disaster began on Wednesday morning after part of a glacier collapsed at an altitude of about 5,200 metres in the Himalayas. The collapse sent ice, rocks and debris down the mountain before the material struck the Lende River.

The resulting surge moved south through Nepal’s Rasuwa, Nuwakot and Dhading districts. At one point, the Trishuli River rose by nine metres within 30 minutes.

The United States Geological Survey later revised its initial assessment of the disaster. It determined that the seismic signal came from the landslide itself rather than an earthquake.

The glacier collapse also created a new lake at the site. Water levels began rising, raising concerns about another possible flood. Authorities temporarily stopped rescue operations while they assessed the danger.

Search and rescue efforts have now resumed after officials determined that the immediate risk from the lake was manageable.

Glacial-hazards scientist Alton Byers told Al Jazeera that the barrier holding back the new lake remains highly unstable. He said it consists largely of loose debris and could pose a serious risk if it fails.

Byers said the safest outcome would be for the lake to drain naturally and gradually. Chinese crews could also attempt to lower the water level manually using hand tools and other methods.

Chinese Premier Li Qiang visited the disaster zone in Gyirong on Thursday. President Xi Jinping also ordered officials to strengthen monitoring of glacial lakes and develop search-and-rescue plans.

International assistance has arrived from India, the United Nations, the Red Cross Federation, Australia, South Korea and the United States.

Officials warn that the death toll could continue to rise as rescuers reach communities still cut off by mud and damaged roads.