At least 33 people have died and eight remain missing in central China, as authorities ramp up rescue and recovery efforts following devastating floods that submerged entire neighborhoods, trapped passengers in subway cars, caused landslides and overwhelmed dams and rivers. Torrential rains have battered Henan province since last weekend, displacing hundreds of thousands of people and causing 1.22 billion yuan (about $190 million) of economic damage, Henan authorities said Thursday. Home to 99 million residents, Henan is one of China's most populous and poorest provinces, with large swathes of farmlands and factories. Zhengzhou, the provincial capital of 12 million people, is one of the worst-hit areas, with 12 killed after being trapped for hours on a flooded subway line. But many smaller cities and villages have also been badly ravaged. With more rains forecast for the region, the death toll is expected to rise as rescue work continues. In Gongyi, a county-level city to the west of Zhengzhou, at least four people were killed as gushing floodwaters swept through the streets. Heavy rains also caused the widespread collapse of homes and landslides, hampering rescue operations. In another city, Xinxiang, rivers have swelled beyond warning levels and seven reservoirs have overflowed, affecting 58 counties and 470,000 people, according to state-run People's Daily. The severity of the flooding was captured by numerous videos shared on Chinese social media, which showed people and cars swept away in surging torrents. On Thursday, stranded residents have continued to call for help on Wechat and Weibo, the country's two largest social media platforms, with some sharing photos and information of their missing family members. One of the most horrifying scenes from the disaster occurred underground on Line 5 of the Zhengzhou subway. During the evening rush hour on Tuesday, hundreds of commuters were trapped in rising water as murky torrents gushed into the tunnel and seeped into carriages. Some posted videos and pleaded for help online. Dramatic videos showing people clinging to ceiling handles to keep their heads above the rising waters shocked the nation and made headlines around the world. In another video, several bodies could be seen lying lifelessly on the platform, as rescuers performed cardiopulmonary resuscitation (CPR) on others. Authorities said more than 500 passengers were evacuated from the inundated subway line, with 12 killed and five others injured. On social media and in interviews with Chinese media, some survivors shared harrowing accounts of how the disaster unfolded on the subway. In a post on microblogging site Weibo, a woman said water started to seep into the subway train soon after it came to a stop in between two stations. Subway staff had first instructed passengers to leave the train and evacuate through the tunnel, but they were soon told to turn back because there was too much floodwater ahead. — CNN