People free a man from the rubble of a destroyed building after an earthquake in Kathmandu, Nepal, April 25, 2015. [Photo/IC]

KATHMANDU - Rescuers dug with their bare hands and bodies piled up in Nepal on Sunday after an earthquake devastated the heavily crowded Kathmandu valley, killing at least 1,900, and triggered a deadly avalanche on Mount Qomolangma.

Army officer Santosh Nepal led a group of rescuers that worked all night to open a passage into a collapsed building in the capital of Kathmandu. They had to use pick axes because bulldozers could not get through the ancient city's narrow streets.

"We believe there are still people trapped inside," he told Reuters, pointing at concrete debris and twisted reinforcement rods that was once a three-storey residential building.

Among the capital's landmarks destroyed in the earthquake was the 60-metre (200-foot) Dharahara Tower, built in 1832 for the queen of Nepal, with a viewing balcony that had been open to visitors for the last 10 years.

Rescuing work is going on at Dharahara Tower. More photos

A jagged stump was all that was left of the lighthouse-like structure. As bodies were pulled from the ruins, a policeman said up to 200 people had been trapped inside.

Bodies were still arriving at one hospital in Kathmandu, where police officer Sudan Shreshtha said his team had brought 166 corpses overnight.

"I am tired and exhausted, but I have to work and have the strength," Shreshtha told Reuters as an ambulance brought three more victims to the Tribhuvan University Teaching Hospital.

Bodies were heaped in a dark room; some covered with cloth, some not. A boy aged about seven lay, his face half missing and his stomach bloated like a football. The stench of death was overpowering.

Outside, a 30-year-old woman who had been widowed wailed: "Oh Lord, oh God, why did you take him alone? Take me along with him also."