It is learnt that the suspect had earlier hacked an occupant of the house, Mohd Joe Abdullah, 23, in the neck and waist with a parang, killing him.
Then, he set the house, which was occupied by 10 people, on fire, killing two others, identified only as Noraini, 62, and Daud, 64.
It was learnt from the Fire and Rescue Department infoblast on WhatsApp, that they received an emergency call about the fire at 3.43pm.
According to Mohd Joe’s grief-striken wife, Sofia Asan, 17, she scooped up her one-year-old daughter and escaped the fire in time through the back door with her mother.
“However, my grandmother who was ill, and my blind grandfather perished in the fire,” she told reporters at the scene.
Sofia said her father, Hasan, 36, was slashed in the neck when he tried to pull the suspect away, so she could escape with her child and mother.
Meanwhile, Sarawak Fire and Rescue assistant director operations Farhan Sufyan Borhan said a team of eight firefighters from the Petrajaya fire station was despatched to the scene.
“On arrival at 4.11pm, the house was 100% destroyed. Firemen discovered the three bodies after the flames were extinguished at 4.40pm,” he said.