Three of the five children injured in a deadly plane crash Tuesday night in northeast China's Heilongjiang Province were in critical condition, doctors said Thursday.

"Four children suffered from airway burns and three were in critical condition. The next 48 hours are crucial," said Wang Yongchen, deputy chief of First Affiliated Hospital of Harbin Medical University, which was caring for ten injured passengers.

Fifteen passengers severely injured in the disaster that killed 42 were airlifted late Wednesday from local hospitals of the crash site, Yichun, to the provincial capital city Harbin and treated at four key hospitals.

"Some kids can speak and you can not see any obvious burns on their skin, but their respiratory tracts are damaged (from the hot fumes) to such an extent that it is life-threatening," Wang said.

The children were treated at the intensive care units at the hospital.

A passenger jet carrying 96 people crashed at the airport of Yichun City in Heilongjiang amid heavy fog late Tuesday night. Forty-two people were killed while the remaining 54 were injured.

Tuesday's crash ended China's remarkable air travel safety record of about 2,100 days -- or 69 months -- without accidents.

In November 2004, a CRJ-200 jet, owned by China Eastern Airlines, crashed shortly after take-off into a park in Baotou City, Inner Mongolia Autonomous Region, killing all 53 people on board and two others on the ground.