Three people were killed and four others are missing after floodwaters swept down a mountain in northern Malaysia and surged through villages, authorities said Thursday.

Water packed with mud, rocks and logs hit settlements close to Mount Jerai on Wednesday, leaving streets and houses swamped and washing away cars.

Properties in the two affected districts suffered severe damage while some people were left trapped inside their houses, emergency workers said.

"I grew up in this village and this is the first time I've seen such an incident," one local resident, Salwa Mohamad Isa, told state news agency Bernama.

"Bridges and roads collapsed, cars washed away and people dying."

Forty people have been evacuated from their homes to community centres, and the search and rescue operation is continuing.

Local NGOs said clearing of forests and mining in environmentally sensitive area could have played a role.

"All these destructive activities in this fragile ecosystem have to be stopped urgently," they said in a statement.

But a senior official has denied that logging caused the floods, instead blaming the intensity of the downpours.

Flash floods are common in tropical Malaysia.

But scientists say climate change increases the risk and intensity of flooding from extreme rainfall, because a warmer atmosphere holds more water.