Kathmandu, Nepal (CNN) -- A small passenger plane crashed in the mountains of western Nepal, killing all 18 people on board, authorities said Monday.
The Twin Otter aircraft left Sunday afternoon from the tourist town of Pokhara, about 200 kilometers (124 miles) west of the capital Kathmandu.
It was on its way to Jumla, a remote town about 600 kilometers (373 miles) northeast of Kathmandu, when it went missing.
The flight usually takes an hour.
"Police have reached the crash site and no survivors have been found," said Bam Bahadur Bhandari, regional police chief of Pokhara. "The bodies are being collected."
The cause of the crash wasn't immediately known. The plane was flying in poor weather conditions as it had been raining and snowing across the country for the past few days.
"The aircraft seems to have hit a mountain" said Bimlesh Karna, deputy director of Nepal's civil aviation authority.
Among the 18 on board were three crew members and a Danish national. Of the 17 Nepalese, one was a child, Karna said.
The 40-year-old Canadian-made Twin Otter aircraft belonged to state-owned Nepal Airlines.
The crash has once again raised concern over Nepal's air safety record. There were two fatal air crashes each year from 2010 to 2012 in this Himalayan country.