HONG KONG — Explosions and fire tore through parts of a poultry processing plant in northeast China on Monday, killing at least 120 people in one of the country’s worst factory disasters in years.

Chinese news reports said many of the workers who had died had been hindered from leaving the factory, the Baoyuanfeng Poultry Plant, because the exits had been blocked or inadequate. The plant began operations four years ago and was considered a major domestic poultry supplier.

Survivors described panic inside the burning plant, as employees unfamiliar with the fire escapes jostled and trampled one another through smoke and flames to reach exits that turned out to be locked.

“Inside and outside the workshop was glowing red, and the lighting and escape indicators were all out,” one worker, Wang Xiaoyun, told the China News Service.