TAINAN, Taiwan (AFP) - Faint signs of life were detected as rescuers raced Sunday to free around 124 people buried under the rubble of an apartment complex felled by an earthquake in southern Taiwan that left 34 confirmed dead, as an investigation began into the collapse.
Sophisticated sensors deployed at the site of the 17-story building detected occasional cries from some of the victims buried deep under many layers of rubble, the New York Times reported.
The death toll rose as emergency workers dug for survivors of the 6.4-magnitude quake that toppled the 16-storey complex of almost 100 homes in the city of Tainan on Saturday.
Officials said an investigation had been launched as questions were raised over the safety of the residential blocks in the complex.
Tainan mayor William Lai said survivors and relatives had reported "violations" but gave no further detail.
"I've contacted judicial units and prosecutors have formally launched an investigation," said Lai.
"We've also commissioned three independent bodies to preserve evidence during the rescue so we can assist the residents if they want to file lawsuits in the future. We will hold the builder responsible if they have broken the law."
Local media reported the construction company that built the complex had gone out of business and also raised questions over the quality of the materials used.
Yueh Chin-sen, whose mother-in-law's family of eight is still trapped, said the residents had complained of defects in the building.
"They complained that the building wasn't well constructed as there were cracks in the walls and tiles fell off after several quakes in recent years," he said. "I hope the government will prosecute the builder on criminal charges as people lost their lives."
Officials said 121 people are still unaccounted for, according to CNA news agency. Earlier, Lai said 103 residents were still trapped "very deep" in the rubble.
"There's no way to get to them direct, it's very difficult," Lai said, adding that rescuers had to shore up the ruins to ensure they were secure before digging.
Emergency workers used cranes, ladders and sniffer dogs to trace and extract survivors in their desperate search.
Several survivors were pulled from the rubble Sunday, more than 24 hours after the quake struck, as rescuers urged those still trapped to stay strong.
One 20-year-old man was freed from the ruins after emergency workers spent eight hours carefully digging him out.
Around 300 have been rescued so far, CNA reported.
Among those confirmed killed by the quake, at least 27 died in the apartment complex collapse, including several children.
Tearful relatives huddled by the ruins, hoping for news.
Chen Yu-mei said her three-month-old son was trapped inside with her sister's family of seven.
"He's a small child, I'm worried sick," she said, her voice cracking and eyes red from crying.
Another woman said her son had been found dead but she was holding out hope for her daughter-in-law and two grandchildren still trapped inside.
"I won't give up hope, I will wait here until I see them come out safe," she said.
Survivors spoke of their terror and relief.
One man told AFP how he was rescued after tapping on a wardrobe that was trapping him.
"I knocked on the closet to get the attention of rescuers who broke the window to get me," said Su Yi-ming, 48, who lived with his family on the sixth floor of the Wei-kuan complex.
Su escaped unhurt while his wife and their two children sustained minor injuries.
The quake struck at a shallow depth of 10 kilometres at around 4:00 am Saturday, 39 kilometres northeast of the island's second-largest city of Kaohsiung.
Taiwan lies near the junction of two tectonic plates and is regularly hit by earthquakes.
The island's worst tremor in recent decades was a 7.6 magnitude quake in September 1999 that killed around 2,400 people.