Bhanu Biswakarma of Kaushilanagar, Kohalpur Municipality-2 set his wife Ganga Bishwakarma and their 2-year-old son Prince Bishwakarma on fire.
Bhanu poured gasoline and set them on fire on Sunday evening over a domestic dispute, said Ganga Bishwakarma.
Victims are under treatment at Nepalgunj Medical College Teaching Hospital. Preparations are underway to bring Prince to Kathmandu due to his severe injury.
Bhanu is at large and the search is on, Kohalpur Police informed.