A landslide killed at least nine people as they slept at a campsite in Malaysia early on Friday, officials said, with search teams scouring thick mud and downed trees for about two dozen people still missing.

The landslide in Selangor state, on the outskirts of capital, Kuala Lumpur, occurred about 3am (1900 GMT) on the side of a road near an organic farm with camping facilities, the state fire and rescue department said in a statement.

More than 90 people were caught in the landslide and 60 had been found safe, with 25 still missing, according to a message on social media by the National Disaster Management Agency.

In addition to the nine dead, seven were injured, it said.

District police chief Suffian Abdullah said the dead were Malaysians and included a child about 5 years old.

Almost 400 people from several agencies had been deployed, with search-and-rescue efforts ongoing, he told a news conference.

The landslide fell from an estimated height of 30 metres (100 ft) above the campsite, and covered an area of about 1 acre (0.4 hectare), according to the fire and rescue department's state director.

Footage from local television showed the aftermath of a large landslide through a steep, forested area beside a road, while other images on social media showed rescue workers clambering over thick mud, large trees and other debris.

"I pray that the missing victims can be found safely soon," Malaysia's minister of natural resources, environment and climate change, Nik Nazmi Nik Ahmad, tweeted on Friday morning. "The rescue team has been working since early. I'm going down there today."

The disaster struck about 50km (30 miles) north of Kuala Lumpur in Batang Kali town, just outside the popular hilltop area of Genting Highlands, an area known for its resorts, waterfalls and natural beauty.

Pictures posted on the Father's Organic Farm Facebook page show a farmhouse in a small valley, with a large area where tents can be set up.

Selangor is the country's most affluent state and has suffered landslides before, often attributed to forest and land clearance.

The region is in its rainy season but no heavy rain or earthquakes were recorded overnight.

A year ago, about 21,000 people were displaced by flooding from torrential rain in seven states across the country.