Kuala Lampur: A landslide killed at least 12 people as they slept in their tents at a campsite in Malaysia early on Friday, officials and witnesses said, as search teams scoured thick mud and downed trees for more than 20 people still missing.

The landslide in Selangor state, on the outskirts of capital, Kuala Lumpur, occurred before 3 a.m. (1900 GMT), tearing down a hillside into an organic farm with camping facilities, the state fire and rescue department said in a statement.

Teh Lynn Xuan, 22, said she was camping with 40 others when the landslide struck.

"I heard a loud sound like thunder, but it was the rocks falling," she told Malay-language daily Berita Harian. "We felt the tents becoming unstable and soil was falling around us. Luckily, I was able to leave the tent and go to someplace safer. My mother and I managed to crawl out and save ourselves."

She said one of her brothers died, while another is in the hospital.

More than 90 people were caught in the landslide and 59 have been found safe, with 22 still missing, according to the fire and rescue department.

In addition to the 12 dead, eight were hospitalised, it said.

One of those taken to the hospital was pregnant, while others had injuries ranging from minor cuts to a suspected spinal injury, health minister Zaliha Mustafa told a news conference.

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

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

The landslide came down from an estimated height of 30 metres (100 ft) above the campsite, and covered an area of about one 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, one of several ministers who were heading to the scene. "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.

News agency Bernama tweeted that all campsites and water recreation areas around Batang Kali had been ordered to close immediately until further notice, citing the minister of home affairs.

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.

Leong Jim Meng, another camper, said he and his family did not expect a landslide as it had not been raining heavily, with just light drizzle in recent days.

"My family and I were trapped when the soil covered our tent," he told Berita Harian. "We managed to run to the parking lot and called the authorities. They arrived quite quickly, about 30 minutes later."

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