The death toll in last week’s devastating flooding in Nepal has risen to 903 people, officials said Monday, as the number of those listed as missing nearly doubled to 4,247.

Among the missing are 592 foreign nationals, Nepal’s National Disaster Risk Reduction and Management Authority said in an update early Monday. State Department spokesperson Tommy Pigott told Fox News on Sunday that about 85 Americans were still unaccounted for.

Rescuers continue to struggle to reach devastated communities days after the massive flooding that stemmed from a glacier collapse on the Nepal-Tibet border region on Wednesday.

“The disaster here is overwhelming,” Ferrin Cole, an operations director at the U.S.-based Crisis Response International, told NBC News on Sunday. “The flood that came down that mountain just wiped out cities. We’re going in as fast as we can to get people the help that they need.”

The disaster has affected more than 90,000 people, according to the Nepal Red Cross.

Morgues in Nepal have been overwhelmed, and a police officer in Chitwan district told Reuters that “more than half” the bodies recovered there were “beyond recognition.”

China has separately reported 16 deaths and 546 people missing in its Tibet region, including hundreds of foreigners. It is unclear how much overlap there is between the Chinese and Nepali missing-person counts.

More than 10,400 people have been rescued, including 277 foreign nationals, according to Nepali officials.

A landslide-dammed lake above the border checkpoint is overflowing, furthering complicating the response effort, China’s state-run media, CCTV, said Saturday ET, but it said the likelihood of a complete breach is “relatively low.”

Meanwhile heavy rain in Nepal has pushed up river levels and prompted fresh warnings for people living along waterways.