Helicopters airlifted critical patients to a hospital during record floods in southern Thailand that have killed more than 100 people.

The Ministry of Natural Resources and Environment dispatched the aircraft to move patients as the deluge cut off transport routes.

Footage shows the helicopter arriving at the Songklanagarind Hospital, where staff rushed to lift the patient onto a gurney, on November 25.

The ministry said: 'This afternoon, one newborn, one child, and 5 five critically ill adults were transferred from Bangkok Hospital - Hat Yai to the evacuation center at Prince of Songkla University Hospital, totaling 6 patients.'

The death toll has climbed to more than 100 as catastrophic floods, described by Prime Minister Anutin Charnvirakul as 'the worst flooding in 15 years', swept through southern Thailand.

Government spokesman Siripong Angkasakulkiat said: 'There have been 33 deaths across seven provinces. Causes of death include being swept away by currents, drowning, electrocution, and landslides.'

Soldiers, volunteers, and local government units have also been mobilised to hasten relief efforts, but they were hobbled by limited phone signal in the area.

The Thai military has sent some 200 boats, 20 helicopters and its lone aircraft carrier, the Chakri Naruebet, to deliver essential supplies and carry out rescue efforts.

Songkhla's Hat Yai district was among the worst-hit areas, which saw a record 13 inches (335 mm) of rain in a single day on November 21.

Songkhla Governor Ratthasart Chidchoo on Monday declared all 16 districts disaster zones and ordered the immediate evacuation of children, the elderly and the sick.

On Sunday, high-clearance trucks arrived to evacuate more than 400 tourists from flooded hotels across the city.

The Disaster Prevention and Mitigation Department said that floods hit nine southern provinces, affecting some 1,128,284 households and 3,221,958 people.

The Southern Eastern Meteorological Centre said a strong monsoon trough was causing the heavy rainfall, which was expected to ease this week.

Thailand and neighbouring countries in Southeast Asia are in their annual monsoon rainy season which sees soaring temperatures followed by powerful rain storms in the afternoon leading to widespread flash floods.