Rescuers have heard possible signs of life 36 hours after 12 workers were trapped when a railway tunnel in Jilin province collapsed in the early hours of Wednesday, China Central Television (CCTV) reported on Thursday.
On Thursday afternoon, the rescuers installed a special pipe with the aim of sending supplies for any surviving workers.
CCTV said on a micro-blogging site that rescuers had heard noise that sounded like tapping on the supply pipe.
The accident happened in a tunnel of the Jilin-Hunchun High-Speed Railway, located in Hunchun city.