Survivors of an inferno at a Chinese poultry processing plant told of their desperate attempts to save others, as relatives of the 119 people killed demanded answers from authorities, media reported Tuesday.

"It was complete disorder, everyone was running," said Chen Hengwu, a worker who escaped unhurt at the Baoyuanfeng plant after it went up in flames in China's deadliest fire for 12 years.

"When I had run out I remembered my wife was also in the workshop. But there was fire and smoke and it was impossible to go back into the workshop to find her," he told the China Daily newspaper.

His wife Pan Xijie, who escaped with slight burns, said there were "chaotic" scenes in the plant during the fire, the latest accident to highlight poor industrial safety standards in China.

Relatives of the victims surrounded police cars, accusing officers of ineffective rescue efforts and demanding an explanation for the disaster, the Southern Metropolis Daily reported.

A senior official at the processing plant has been detained, a local official told AFP Tuesday, after the blaze spread in minutes on Monday following a blast suspected to have been triggered by a chemical leak.

"The legal representative has been placed in custody and (the company's) assets have been frozen," an official with the ruling Communist Party's propaganda department in Changchun, who declined to be named, told AFP.

The representative's role in the poultry firm was not disclosed.

The fire at the plant at Dehui, around 100 kilometres (62 miles) northeast of Changchun, the provincial capital of Jilin province, started in a workshop which had only one open door, media reports have said.

"I heard an explosion first, then someone shouted 'Fire!'" 39-year-old worker Guo Yan told the China Daily.

"The workshop was engulfed in a sea of flames. The light went out and people immediately started to run.

"The gate to my workshop was blocked, so I ran towards another exit. Most people were running in that direction as well. Many ran into each other and fell over in a pile on the floor."

Up to 300 people were working inside, media reports said. About 70 people were reported injured but it was not clear how many were still missing.

Authorities on Tuesday raised the toll to 120, but then revised it back down to 119, saying one victim had been double-counted.

The blaze was the country's worst fire for more than a decade, according to listings on Internet portal Baidu. On December 25, 2000, an inferno at a shopping centre in Luoyang in the central province of Henan killed 309 people.

China's President Xi Jinping is currently visiting several Latin American countries. Official media said he ordered "all-out rescue efforts" but a posting on China's Twitter-like Sina Weibo said: "Had this been happening in other countries, the national leaders would cut off their trips abroad and come back."

Authorities are still investigating the cause of the blaze, according to the Jilin government.

State news agency Xinhua pointed to "poor safety awareness and inadequate supervision" causing "a string of work safety accidents that have resulted in heavy casualties this year".

"The accidents are also the result of companies' desire to pursue profit at the cost of safety, as well as the laziness of officials who fail to fulfil their responsibilities," a commentary by Xinhua said late Monday.

Wang Rulin, party secretary of Jilin, has said the government will assign a "working team" to the family of each victim and ordered officials to "resolutely prevent major mass incidents", according to a statement on the Changchun government website, using a euphemism for social unrest.

He also vowed to strengthen control over the Internet to "resolutely prevent malicious exaggeration, rumours spreading and firmly prevent the misleading of public opinions and the undermining of stability".