Four members of a family, two of them children, were found brutally murdered at their house in Sibu between 7am and 7.30am today, and a badly injured boy is fighting for his life in hospital, police said.

Sarawak police deputy commissioner Law Heng Soon said the dead have been identified as businessman Ling Tong Hock, 36, his mother Leong Nyuk Lan, 76, son David Ling Chei Qi, 10, and daughter Amy Ling Zi Jiun, seven.

He also said that another of Tong Hock's sons, Kelvin Ling Chei You, eight, is under intensive care at Sibu Hospital for a bad slash wound on the head.

Law said Tong Hock's wife, Li Xiao Lan, 28, fled unharmed through a window to a neighbour's house after she heard a commotion downstairs and some people trying to kick down the bedroom door of the house at Lane 13B1, RTM Road in Sibu.

He appealed to eye-witnesses to come forward to help the police and asked the media not to make any speculation which can hamper investigations.

The police will bring in forensic experts either from Kuching or Bukit Aman if necessary, he said.

"I have come here specially for this case to see what kind of help we can offer. We will not leave any stone unturned in our investigation," he said.

Sibu police chief ACP Shafie Ismail said police have ruled out robbery as the motive as the house was not ransacked and nothing seemed to have been removed from it.

He said police will study the CCTV recording at the house.

Meanwhile, Law said Sibu is still a very safe town and the people should not be unduly alarmed.

He said there were two murder cases here last year, one of which has been solved.

- Bernama