The deceased are Narayan Khadka, 50, and Som Bahadur Tamang, 16, of Dhorthali-4, according to District Police Office.
The injured are being treated at Sadabahar Hospital in Khadichaur.
Two Nepal Army soldiers electrocuted to death in Chitwan
The event will take place at the National Assembly Hall on Exhibition Road, Kathmandu, and will focus on the manifesto unveiled under the leadership of party President Gagan Thapa.