The storm made landfall in Vietnam on Monday, forcing tens of thousands of people to evacuate, before sweeping across Laos and northern Thailand, bringing torrential rain.

Five people were killed and 15 injured in 12 provinces in northern Thailand, according to the Department of Disaster Prevention and Mitigation.

Provinces including Nan, Chiang Rai, Mae Hong Son province were hit particularly hard, with flash floods destroying bridges and cutting off communities.

Since Sunday, at least seven people were reported missing, with more than 1,800 households and 6,300 people affected by the typhoon, which weakened to a tropical depression as it moved inland.

"The water level is likely to increase in some areas," the disaster agency said in a Facebook post.

On Wednesday, two people were killed in landslides in the popular northern tourist destination of Chiang Mai.

The kingdom's meteorological department forecast continuous rain through next week across the north, northeast and central regions.

Thailand regularly experiences heavy rainfall from June to September, but experts say human-induced climate change has intensified extreme weather, making conditions increasingly unpredictable.

Widespread flooding across Thailand in 2011 killed more than 500 people and damaged millions of homes around the country.