The death toll from last week’s devastating flash floods and landslides in Nepal and China has surpassed 1,000, while more than 4,400 people remain missing as rescue and recovery operations continue.

Nepal’s National Disaster Risk Reduction and Management Authority said Tuesday morning that 987 people had been confirmed dead in the country, while 3,916 remained unaccounted for. More than 11,800 people had been rescued. On the Chinese side of the border, at least 16 people had died and 546 were still missing, according to Chinese state broadcaster CCTV.

The scale of the disaster has created an enormous challenge for authorities trying to identify victims and reunite them with their families. Nepalese authorities have begun burying hundreds of unidentified bodies in mass graves after morgues were overwhelmed and many victims became difficult to identify following days in the river.

At a recovery center in Bharatpur, Sub Inspector Hari Sharan Dhakal is helping families search for missing relatives and identify recovered bodies. His team has a list containing 837 names, addresses, contact information and photographs supplied by relatives. However, many bodies have changed significantly after spending days in the water.