POKHARA, Nepal — Two workers in Nepal were pulled out alive from a hydropower tunnel on Friday, some nine days after devastating floods swept the Himalayan region and left thousands of people dead or missing.

In a rare glimmer of hope, emergency teams rescued two male workers — a mechanical foreman named Sanjay Sah, 30, and a mechanical supervisor named Kabir Maharjan, 45, according to Nepal’s army and the country’s National Disaster Risk Reduction & Management Authority.

Rescue officials said the voices of other workers could be heard inside the tunnel at the Trishuli 3A hydropower plant along the Trishuli River in Nepal’s border district of Rasuwa. At least 557 workers are still believed to be missing there, with about 115 believed to be trapped in the main tunnel, according to the Independent Power Producers Association of Nepal.

Nepal’s army released images of the dramatic rescue on its official Facebook page, including one showing the first rescued worker covered in mud and being carried from the site on a rescuer’s shoulder.

“When hope is alive, even the impossible becomes possible,” the image caption read.

Officials said both men were flown to a hospital in Kathmandu, the capital, for treatment.

“I can’t explain what we are feeling at the moment. We are just grateful to God,” Amir Maharjan, the brother of one of the rescued workers, told The Associated Press. He said the family was on its way to the hospital to see him.

Army spokesperson Brig. Gen. Raja Ram Basnet said one of the survivors told rescuers that more people were still alive inside the tunnel.

“We are waiting for the rescue of more and more people,” Nepal’s communication minister, Bikram Timilsina, wrote on his Facebook page.

More than 900 workers are missing from about a dozen hydropower projects in Nepal, with roughly 500 believed to be trapped in tunnels, according to local officials.

Rescuers have been struggling to access the hydropower projects, many of which are in remote, mountainous areas, with bad weather adding to the difficulties. The flooding damaged roads and collapsed sections of tunnels, filling them with mud and other debris and blocking some entrances.

Aided by foreign experts, rescue teams have been working around the clock using controlled blasts, excavators and earth-moving equipment to try to reach the trapped workers amid concerns about air quality in the tunnels and the workers’ access to drinking water.

Authorities in Nepal say at least 1,287 people were killed and more than 5,000 remain missing after the Aug. 26 disaster, which is believed to have been set off by a high-altitude glacier collapse on the border between Nepal and China’s Tibet region.

Rescue efforts are also still underway in China, where a mudslide hit a major land crossing between the two countries, with the only road to the site in Tibet’s Gyirong county fully reopening only on Wednesday. Chinese officials say at least 21 people were killed and 541 are missing on the Tibet side of the border.

More than 800 foreign nationals are among those missing in the area, which is popular with trekkers and pilgrims. According to the State Department, 75 Americans remained unaccounted for as of Wednesday, while 16 had made their way to safety.

Sunil Pandey reported from Pokhara, Nepal, and Adela Suliman from London.