At least 18 people have died after torrential rains inundated towns an cities in central China – trapping people in a flooded subway system in water up to their necks

Twelve of the deaths reported so far occurred in the city of Zhengzhou, Henan province, after the city’s underground network flooded with horrifying videos showing people trapped in train carriages filling with water while awaiting rescue.

Another four were reported dead in the nearby town of Gongyi, while five were injured and another 200,000 displaced in what is believed to be the heaviest rainfall in the region for 1,000 years.

Disaster struck between 4pm and 5pm Tuesday as an incredible 22 inches of rain – seven months’ worth – fell on already-saturated ground, triggering flash floods and causing rivers and reservoirs to burst their banks.

Train tracks turned to rivers in Zhengzhou as commuters on the city’s ‘Line 5’ were trapped in flooding carriages than plunged into darkness as the power went out.

Survivors recalled fear gripping them as the waters rose, but said the most terrifying thing was when air inside the trains started to run out.

Parents could be seen holding their children up above the floodwaters as it leaked in around the carriage doors, rising above seat level and halfway up their chests.

Others showed water flowing freely down train track as bemused passengers stood on the platform, before beginning to evacuate.

One video showed a woman’s hand with painted nails, gently pushing at the carriage window, a stirring sign of incredulity at the surging water level outside – a moment of dread before the inevitable breach of the carriage doors.

‘Water was leaking from the cracks in the door, more and more of it, all of us who could, stood on the subway seats,’ another woman said on Weibo.

She was making her way home around 5pm on Tuesday when her train halted between two stations close to the city centre.

Another user on Weibo recounted being forced back into a carriage after failed attempts to evacuate.

‘In the half-hour that, followed the water level became higher and higher inside the train, from our ankles to our knees to our necks.’

‘The power went out. Half an hour later it got hard to breathe.’

Suddenly the glass was smashed by rescuers, who state media said also cut into the stricken carriages from above to pull the passengers out to safety.

Witnesses added that many city buses, which run on electricity, had been deactivated during the heavy rain as they could not run – driving more people on to the subway and exacerbating the crisis.

The worst-affected area was on Line 5 of the subway between Haitansi and Shakoulu stations, where passengers were reportedly trapped for hours in train carriages filling with water, waiting to be rescued.

A male survivor named Zhang told state broadcaster CCTV: ‘My shirt, my backpack – everything I could throw away, I threw away. The people around me clutched onto the railings as about a dozen of us were climbing (out of the tunnel).’

At around 7.30pm a woman identified as Xiaopei sent out an appeal for help on social media, according to the South China Morning Post.

‘All emergency rescue units and firemen, please come save us!’ said one of her messages sent at 7.32pm ‘We are trapped in a Line 5 tunnel. Please help spread this message. The water inside the train is chest-deep. I can no longer speak, please help! SOS.’

At 7.46pm she made a final message before her phone’s battery died, saying the water had reached her neck. It wasn’t until over an hour later – at 8.50pm – that she and her fellow passengers were rescued.

Another woman spoke of the fear that gripped her and other passengers, saying there were children, pregnant women and elderly people among them. Outside the carriage, they could see the water level had risen above their heads.

Rescuers began pumping out water, but she was afraid that it would be too late.

‘Looking at the overwhelming flood, I felt hopeless, preparing myself for the fact that I wouldn’t make it out alive. When I saw the water level had reached our heads, I began sending out my last goodbye messages and arranging affairs after my death with loved ones,’ the woman told Bingdian Weekly.

Elsewhere, floods triggered a huge explosion at a metalworks in the city of Denfang after a nearby river burst its banks.

The blast was triggered when water got into a tank filled with hot metal alloys, causing a reaction which blew the tank apart and destroyed part of the factory.

Fortunately, workers had been evacuated two hours earlier so nobody was injured in the explosion.

Chinese President Xi Jinping declared the deadly flooding in central China’s Henan province ‘extremely severe’, adding: ‘Some reservoirs had their dams burst… causing serious injury, loss of life and property damage.’

The city’s subway operator said in a statement on Tuesday that it would close all stations on all its lines due to the bad weather.

On its official Weibo account, the fire service shared reports that passengers were being rescued from stranded trains, but did not post its own statement.

One passenger’s account said fire and rescue workers had opened a hole in the roof of her carriage and evacuated passengers one by one.

Weather authorities have issued the highest warning level for central Henan province as CCTV showed submerged cars, shuttered shops and residents of flooded streets being rescued in rafts, one clutching a baby.

Footage showed one man sitting on top of his half-submerged car in an underpass.

More than 10,000 people had been evacuated as of Tuesday afternoon, said provincial authorities, warning that 16 reservoirs had seen water rise to dangerous levels as downpours ruined thousands of acres of crops and caused damage amounting to around $11million.

Around 260 flights have been cancelled.

Floods are common during China’s rainy season, which causes annual chaos and washes away roads, crops and houses.

But the threat has worsened over the decades, due in part to widespread construction of dams and levees that have cut connections between the river and adjacent lakes and disrupt floodplains that had helped absorb the summer surge.

Earlier this month hundreds of flights were cancelled in the capital Beijing and other nearby cities with schools and tourist sites closed as torrential downpours and gale-force winds battered the region.