The two Himalayan nations have been lashed by heavy rains in the last three days as the annual monsoon season begins.
Flash floods triggered by heavy monsoon rains have washed away a remote mountain camp in Bhutan, killing 10 people and injuring five, while floods in neighbouring Nepal left at least three dead and seven missing, authorities said.
The Bhutan villagers, who had been collecting cordyceps, a fungus used in medicine, were sleeping when the floodwaters hit just after midnight.
Their camp near Laya, about 60km (37 miles) north of the capital, Thimphu, was washed away, local media reported.
“Our hearts are with the people of Laya today, as we hear about the tragedy that struck a group of cordycep collectors in the highland,” Bhutan Prime Minister Lotay Tshering said in a statement.
Two helicopters were mobilised to evacuate the injured and rescuers, and the armed forces were heading to the site which can only be reached after 11 hours of walking from the nearest road.
Villagers in Bhutan and neighbouring Nepal go to high meadows every year to collect cordyceps which are believed to have potential health benefits.
The villagers were camping by the side of a small stream between two small hills, The Bhutanese newspaper said.
“It is believed they were washed away by the flood coming down the stream”, it said.
Three dead, seven missing in Nepal
In Nepal, police spokesman Basanta Bahadur Kunwar said that rescue teams have recovered three bodies – two in western Nepal and one in the country’s centre.
“Security forces have been working with locals to rescue affected households and relocate to safer places,” Kunwar told DPA news agency.
Home ministry official Dil Kumar Tamang said seven people were missing after overnight rains in Sindhupalchowk district, which borders the Tibet region of China, triggered flash floods in the Melamchi river inundating dozens of homes.
“We are collecting details of losses,” Tamang told Reuters news agency.
Witnesses said several people in Melamchi had moved to higher grounds with their belongings while army helicopters were rescuing those trapped in marooned houses.
Authorities urged people living along the Narayani river, which flows into India as Gandak, to remain alert as the river was flowing above the danger mark.
More than three days of rainfall caused the Melamchi river to rise, sweeping away several houses and damaging bridges and road infrastructure in two municipalities northeast of Kathmandu.
“We have not been able to access the true extent of the damage,” Khanal told DPA.
Nepal and Bhutan have been lashed by heavy rains in the last three days as the annual monsoon season begins. Monsoon-induced disasters are common in the two nations owing to their mountainous topography and big rivers.