At least two people died and 10 were injured in an explosion and fire that swept through an animal feed plant in Omaha, Nebraska, on Monday, local authorities said.

Douglas County district attorney Don Kleine confirmed the two deaths and said that there could be more fatalities, according to the North Platte daily.

Meanwhile, Omaha fire chief Bernard Kanger acknowledged at a press conference that there had been "fatalities," adding that there were 17 known survivors, but he said that the number of victims could not be specified at present because authorities had not had the chance to "clear the entire structure" - part of which collapsed - at the International Nutrition plant.

Thirty-eight people were working at the plant when the blast occurred at mid-morning. Apart from the two known fatalities and 17 survivors, this would leave 19 people unaccounted for.

Authorities have confirmed that 10 people were injured and admitted to nearby hospitals where four of them are in serious condition.

Plant worker Nate Lewis told local television station KETV that he was inside the building when he heard an explosion and things began falling around him. The lights went out and he could see fire in the building, but he managed to find a path outside to safety. EFE