BUENOS AIRES - The Chinese national injured in Wednesday's train crash in Argentina remained under medical treatment Thursday with worsened conditions.

The 24-year-old Chinese man, surnamed Sun, was in the first carriage of the crashed commuter train when the tragedy occurred. He was airlifted to a hospital after suffering severe wounds from the impact.

Hospital sources said there was no serious damage to the victim's internal organs but his conditions were worse than initially considered. The injured man has been put under intensive care.

Meanwhile, a Chinese woman, previously reported as missing, has been confirmed dead after the train crash which killed at least 50 people and injured 703 others.

The packed train crashed onto station buffers at around 8:30 a.m. local time (1130 GMT) Wednesday, on a railway line linking Buenos Aires to its western suburbs.

Argentina's government has declared a two-day mourning for the tragedy with flags at half-mast.