The accident occurred when the tour bus skidded and crashed in Kota Marudu.
The fire department says 40 other passengers and trailer driver unhurt.
The whole family was travelling on the ill-fated express bus
Guan Eng makes the call after expressing deep condolences on the tragedy which killed eight.
UPDATED 9.10PM | The early morning crash near the Juru Toll Plaza involved two factory buses.
Police say among those killed was the 47-year-old bus driver who had three records, including for speeding.
Last year one of the company's four directors withdrew from the company and the bus involved in the accident was given to the director.
Fixed a time limit for bus drivers to drive in a day, which should be eight hours a day, says consumer group.
A thorough investigation to identify the cause of the crash is being done, says Malaysian Institute of Road Safety Research.
Accident that killed 14 will be thoroughly investigated, says Johor deputy police chief.