The victims were en route to Akaladevi Temple at Sirshekot from Galyang when their jeep plunged some 200 metres down the road at Senithumka area of Pelakot village in Syanjga district, according to the District Police Office.
The accident site is 300 km west of Kathmandu.
The mishap occurred at a time when all the Nepalese people were celebrating Holi festival.
The deceased include a 16-year-old girl and the rest were aged between 30 and 40 years.
The reason behind the accident is not yet known.
The people of Kathmandu Valley and other hilly regions of the country celebrate Holi on full Moon day in the month of Falgun, whereas people in the Terai region in the southern plains observe the festival the next day.