According to local media reports, 14 customs officials went missing following the flooding.

District Police Office chief Bipin Regmi told The Himalayan Times that three unidentified bodies were recovered from the banks of the Trishuli River in Nuwakot — two at Simchaur and one at Kolputar.

The flash flood struck the mountainous Rasuwa district, located north of Nepal's capital Kathmandu and bordering Tibet.

The Nepal Army, Armed Police Force and Nepal Police have launched rescue operations, with helicopters deployed to assist in relief and evacuation efforts.

Officials told the BBC that they believe the flooding was caused by melting snow that had accumulated in the Bhote Koshi River, which flows from Tibet into Nepal.

Several downstream districts have been placed on high alert. While officials expect the damage to be severe, it is too early to assess the full extent of the destruction, Rasuwa Chief District Officer Narendra Pariyar told BBC Nepali.

According to media reports, 12 people have been rescued so far.

Meanwhile, Nepal Prime Minister Balendra Shah held an emergency meeting to assess the situation and review rescue and relief efforts.

"Today's meeting held at the Prime Minister and Council of Ministers, Singhadurbar, discussed with MPs from Rasuwa, Nuwakot, Dhading, Gorkha and Chitwan on flood damage, condition of settlements in coastal areas, rescue and relief work," the official Facebook handle of the Prime Minister said.

"During a discussion with MPs from flood affected areas, the Honorable Prime Minister informed that the government has been fully committed to the safety and relief of the affected citizens, the lower coastal region has been given a clear direction to the bodies to take additional caution and transfer the displaced to safe places immediately," the post added.