Rescue workers search for survivors amid the debris of Xinjia Hotel in the Licheng district of Quanzhou, southeast China's Fujian province, on March 8, 2020, a day after the hotel collapsed. (LIN SHANCHUAN / XINHUA)

The death toll from Saturday's hotel collapse in Quanzhou, Fujian province, increased to 13 on Monday evening as rescuers brought in heavy machinery to help with the increasingly difficult rescue work.

Fifty-two people had been pulled out of the wreckage of the Xinjia Hotel in the city's Licheng district as of 8 pm on Monday and 13 of them were dead, said the rescue headquarters.

Of the 71 people trapped by the sudden collapse at around 7:15 pm on Saturday, 19 remain trapped. Over 1,000 rescuers have been involved in the rescue efforts.

Rescuers had to crawl into gaps among steel frames, concrete and iron plates to detect life while resorting to heavy machines and electric saws to dig downward.

However, they only managed to pull out three people from the rubble on Monday as of 8 pm. It took rescuers about four hours to get one of them out.

Ye Zhiyong, a commander with a Fujian fire rescue team, said the rescue work has been increasingly difficult as rescuers dig further downward

Ye Zhiyong, a commander with a Fujian fire rescue team, said the rescue work has been increasingly difficult as rescuers dig further downward.

"The seven-floor steel frame building was completely reduced to rubble. The structures of different floors piled up and the beams and pillars all crowded together, making the situation extremely complicated," he said.

Ye said that five professional rescue teams from nearby cities have arrived in the city to help with the rescue efforts.

ALSO READ: East China hotel collapse death toll rises to 10

In a video conference on the collapse on Sunday, Huang Ming, Party secretary of the Ministry of Emergency Management, urged all-out efforts to save the trapped as long as there is still a gleam of hope.

The collapse trapped all but nine of the 80 people in the hotel, a facility for medical observation after the novel coronavirus outbreak.

Licheng district government said 13 people injured in the accident remain hospitalized in the Second Affiliated Hospital of Fujian Medical University, and five of them are in serious condition.

The hospital has designated two zones to treat the injured to avoid cross infection and each of the patients is in a separate room, it said in a media release. "All patients are in stable condition," it said.

An investigation into the cause of the collapse continued on Monday.