The incident occurred when the truck was negotiating a narrow wet stretch of road while returning from their work site near Tala Dam at Wangkha in Chukha district at around 8.30 pm.day.

Police said 10 workers died on the spot with their bodies found smashed and scattered beyond recognition.

Two died after reaching the Tsimasham hospital. Of the six injured, the condition of three are critical and have been shifted to Thimphu referral hospital.

The truck belonged to Hindustan Construction Company (HCC). The bodies have been handed over to the Tala project manager S K Sarkar.

In a separate incident, a 22-year-old youth working as a helper in a truck died yesterday after the vehicle, carrying three passengers, plunged 247 feet below the road at Sisiding, about three kilometres from Thinleygang district.