Beijing (AFP) -
Police in central China announced the detention of nine people on Sunday over a collapsed building, as increasingly desperate rescuers comb the debris for any survivors.
The building, in Changsha city, housed a hotel, apartments and a cinema. It caved in Friday afternoon, leaving a gaping hole in the dense streetscape.
At least 18 people were trapped and another 39 were incommunicado, according to city mayor Zheng Jianxin.
Five people were rescued from the pancaked structure overnight Friday.
Changsha police said on social media that the building's owner and three others responsible for its design and construction were detained Sunday on suspicion of 'major responsibility for an accident'.
Another five people, all members of a private building inspection firm, 'provided a false safety report after conducting a building safety audit of the hotel', the statement on Twitter-like Weibo said.
No cause for the disaster has yet been given by authorities.
Changsha's mayor vowed to 'seize the golden 72 hours for rescue and try our best to search for the trapped people' in a news briefing Saturday, adding that over 700 first responders had been dispatched to the scene.
State media showed firefighters -- backed by a digger -- cutting through a morass of metal and sheets of concrete, while rescuers shouted into the tower of debris to communicate with any survivors.
A crowd gathered as chains of rescuers removed pieces of brick by hand, allowing experts a deeper look into the wreckage.
Some of the injured were rushed away on gurneys, while sniffer dogs combed the area for further signs of life.
President Xi Jinping on Saturday called for a search 'at all cost' and ordered a thorough investigation into the cause of the collapse, state media reported.
A top Communist Party official was dispatched to the scene -- an indication of the severity of the disaster.
China's minister of emergency management Huang Ming urged officials to 'thoroughly eliminate all kinds of hidden safety risks' in a Saturday meeting.
Building collapses are not uncommon in China, due to weak safety and construction standards as well as corruption among officials tasked with enforcement.
In January, an explosion triggered by a suspected gas leak brought down a building in the city of Chongqing, killing at least 16 people.