Angry over his younger brother securing a government job on compassionate grounds, a 30-year-old man allegedly set two rooms of their house on fire, killing four members of the family and injuring four others in West Bengal's Malda district, police said Monday.
The incident occurred at Madantola village under Manikchak police station, they said.
Accused Makhan Mondal allegedly poured petrol in two rooms of the tiled-roofed hut on Sunday night when the family members were asleep.
Makhan's younger brother Gobinda, 28, elder brother Bikash, 32, and Goninda's two daughters - aged 3 and one-and-a-half years - were charred to death, police said.
The two children died on the spot while Bikash and Gobinda succumbed to injuries in hospital, they added.
Bikash's wife, son and daughter and Gobinda's wife were admitted to the Malda Medical College and Hospital in a serious condition, police said.
Mother of the brothers was sleeping in another room and she escaped unhurt, they said.
Police said Makhan, whose wife is now at her parents' place, was absconding.
Police and family sources said Gedu Mondal, a worker of the National Volunteer Force (NVF), had died in harness sometime back and Gobinda got the job on compassionate grounds with help from Bikash, leaving Makhan angry.
The brothers were engaged in agricultural work.
Their other brother Lakshman lives in Delhi.