Thailand airlifted patients and flew critical supplies, including oxygen tanks, into a submerged southern city on Wednesday, as the death toll from some of the region’s worst floods in years climbed to 33.

Floods have swept through nine Thai provinces and eight states in neighbouring Malaysia for a second successive year, prompting both countries to evacuate nearly 50,000 people.

In Indonesia, 8 to 13 people are estimated dead following floods and landslides this week, while one has died in Malaysia.

Three days of torrential rain starting last week dumped record volumes on Hat Yai, Thailand’s southern commercial hub, flooding hospitals and stranding thousands on rooftops. On Friday, the city received 335 mm of rain, its highest in a single day for 300 years.

The Thai military has mobilised boats, helicopters and even its lone aircraft carrier to deliver supplies and evacuate the sick.

Extreme weather events can become more frequent as a result of global warming, with higher sea surface temperatures supercharging tropical storms.

“There have been 33 deaths across seven provinces,” Thai government spokesperson Siripong Angkasakulkiat said in Bangkok. “Causes of death include being swept away by currents, drowning, electrocution, and landslides.”

PUBLIC CALL FOR EQUIPMENT

Without electricity, parts of the city were still in darkness late on Wednesday and swamped by almost waist-high swirling brown water, according to a Reuters journalist.

Rescue workers pushed boats through flooded neighbourhoods, some of them loaded with residents pulled out of their homes.

In an update on social media, provincial authorities said that flood waters in many areas were gradually receding but currents remain strong, hindering rescue operations.

The Thai military has pressed some 200 boats and 20 helicopters into service in the area, and authorities have received appeals for help from around 77,000 people through social media channels, according to Siripong.

Military helicopters dropped supplies to residents gathered on rooftops, some of them waving for help. Other aircraft flew into the area with generators, oxygen tanks and water, social media posts by the air force and navy showed.

Thailand’s only aircraft carrier, Chakri Naruebet, which set out from its home port on Tuesday, had joined the relief effort, providing air support, the navy said.

The government made a public call for equipment, including boats and jet skis.

Three consecutive days of downpours since last Wednesday dumped 630 mm (24.8 inches) of rain around Hat Yai, higher than a previous peak of 428 mm in 2010, according to the country’s Geo-Informatics and Space Technology Development Agency.

The weather system has moved away towards the Strait of Malacca and intensified into a tropical cyclone that will move towards Indonesia, the Thai Meteorological Department said.

HOSPITAL EVACUATIONS IN THAILAND AND MALAYSIA

Floods have affected more than 980,000 homes and over 2.7 million people in Thailand, the interior ministry said.

Flood waters had inundated the first floor of Hat Yai’s main government hospital treating 600 patients, around 50 of them in intensive care, public health ministry official Somrerk Chungsaman told Reuters.

“Today, all intensive care patients will be transported out of Hat Yai Hospital,” he said.

At another hospital, an army helicopter evacuated a critically ill elderly woman, who was surrounded by medical staff on the aircraft then wheeled away from the rooftop helipad of another facility, according to a handout video.

In Kangar, the capital of Malaysia’s Perlis state, which borders Thailand, workers moved patients out of the Tuanku Fauziah Hospital on gurneys through knee-high water, according to a Reuters journalist.

‘AT LEAST SEND THEM SUPPLIES’

Despite the push by Thailand’s military, which took over relief efforts on Tuesday, some residents of Hat Yai and surrounding areas who were still waiting to be rescued posted desperate pleas on social media.

Auntita Taechinchotikan, 33, who lives in Bangkok, had only managed to make contact with her stranded brother and his family early on Wednesday.

“I’ve tried contacting every rescue team, and they’ve all responded, but no one has been able to reach the house,” she told Reuters.

Ten family members were trapped in two buildings in Hat Yai, including her parents and young children, said Auntita.

“If they can’t take them out, then at least send supplies,” she said. “I don’t know how much food they have left to survive.”