BEIJING - At least 20 people have died and 19 are missing in northern China after heavy rainstorms battered Beijing and neighbouring Hebei province for a fourth day in a row, officials said on Tuesday.

Among the dead in the capital were two rescuers who lost their lives in the line of duty, including a 30-year-old firefighter from Shandong province. 

Initially, 27 people were reported missing in Beijing, but officials said later on Tuesday afternoon that 14 had been located – they were telecommunications workers trying to restore connection to a mountainous region west of the city.

In Hebei province, nine people died during the recent rains and six remain missing, according to an official statement. More than 540,000 residents have been affected.

Doksuri, a former super typhoon, has swept northwards over China since making landfall in Fujian province last Friday after ripping through the Philippines last week.

Officials say about 127,000 people have been evacuated in Beijing because of incessant rain that has wreaked havoc across the city, causing rivers to overflow and landslides in the more mountainous parts of the city.

The rains are some of the heaviest in Beijing in years. The average rainfall in July was 337.2mm, nearly double the 171.2mm in the same month in previous years.

The July downpours are the heaviest in the city since July 2012, when 79 people were killed and tens of thousands evacuated.

Videos on social media show rivers turning into dangerous rapids, washing away cars and small buildings.  

About 40 flights were cancelled and at least three trains have stalled on railway lines, trapping passengers on board. 

Military helicopters were activated on Tuesday morning to deliver supplies to the stranded train passengers, who said they have been trapped for at least 30 hours and had run out of food and water.

Local media on Monday broadcast chaotic scenes from within the trains, with a train attendant seen trying to reassure passengers while on the verge of tears. 

The hardest hit has been mountainous Mentougou district west of the city, where water, power and telecommunication lines have been down since Monday evening. 

Municipal workers have been working to restore power lines, while 45 water tanks have been brought in as emergency supplies for the 150,000 households without running water.

The area is home to about 400,000 residents. 

Product tester Hu Ruijie, 29, who lives and works in Mentougou, said he was able to wash up at work because the company has its own water storage tank. 

“Fortunately for my colleagues and me, we all live quite far from the badly affected area, so we have still been able to come to work,” he told The Straits Times. 

“But at the height of the storm on Monday afternoon, the floods were about the height of a car tyre.” 

Hundreds who have lost contact with their families and friends have taken to social media to appeal for more information. 

“What is happening in Qingshui town in Mentougou? I don’t have any information at all, and my parents have been uncontactable for over 24 hours. I can’t get through to any emergency helplines, but I don’t see reports of any rescue helicopters heading in that direction,” social media user Ah Han posted just after noon on Tuesday. 

When contacted by ST after 2pm, the retail assistant said others have told her that villagers living in the same area as her parents have been evacuated to a nearby town on higher ground.

“But until I speak to them myself, I’m worried to death,” she said. 

State media reported that Chinese President Xi Jinping called for “every effort” to be made to rescue those lost or trapped by the rains. 

The local authorities must do a “good job in the treatment of the injured” and minimise casualties, reported state broadcaster CCTV.

“It is now a critical period of flood control, and all regions and relevant departments should do a good job... in ensuring protection for people’s lives, property, safety, and ensuring the stability of society at large,” Mr Xi was quoted as saying. 

The government has also set aside 110 million yuan (S$20.6 million) for relief and repair works.

Meanwhile, censors have also jumped into action, limiting search results on social media platform Weibo and restricting certain videos from being forwarded on WeChat.

A search of the hashtag “Heavy rains in Beijing’s Mentougou led to large numbers of cars getting washed away” resulted in a message saying results could not be displayed due to “relevant laws, regulations, and policies”.

But the videos can still be accessed when a separate search is made with “Beijing heavy rains”.

During the regular evening news broadcast, Mr Xi’s comments on the floods were the top news item, but no footage of the rains and rescue efforts was shown. Instead, news anchors simply read from a statement that had been released in the afternoon by CCTV.

State media on Tuesday evening reported that some 47,000 people in Tianjin, south-east of Beijing, have been relocated in anticipation of floods that are expected to reach the city later that night.

With the rains easing up on Tuesday afternoon, reservoirs across Beijing and Hebei have begun releasing water into surrounding rivers.

Official notices have warned that roads near rivers will be closed as flood water is released, while the public have been told not to go near rivers. 

As flood waters recede, the extent of the damage is beginning to emerge. Numerous roads, bridges and embankments have been damaged by the deluge, while scores of mud-covered vehicles – washed away during the storm – have become visible.