Norazam Khamis, director of the Selangor State Fire and Rescue Department, told reporters on Friday that two of the victims were “believed to be a mother and her child in a hugging position buried under the earth”.
Officials said the farm did not have a license to operate the campsite and that its operators would be punished if they were found breaking the law.
Prime Minister Anwar Ibrahim visited the area late Friday and said financial aid would be given to the families of those killed or injured in the disaster.
Selangor state chief minister Amiruddin Shairi tweeted that all picnic and camping sites in the state would be closed for a week.
Landslides are common in Malaysia after heavy rains, which are regular towards the end of the year, and can be followed by bad weather.