Search crews have recovered another body from the Imperial Sugar refinery devastated by a massive explosion on Friday, bringing the number of confirmed deaths to six.

Insurance and safety fire commissioner John Oxendine told The Associated Press, crews removed the body from the debris of the Georgia refinery shortly before ending search operations at sunset.

"The body was found in the final sweep," said Oxendine, who told The AP he got the news from Port Wentworth Fire Chief Greg Long. "It is in the custody of the medical examiner."

Dozens of workers were sent to hospital with burns and other injuries from the smoulding remnants of the plant last week, where two more workers are still missing.

Officials stopped the search at sunset on Sunday after searching most of the plant, but leaving part of the refinery complex that was still burning and where the buildings were dangerously unstable.

Long said search crews had covered 95% of the massive refinery, but sugar still burning in two of the refinery's three badly damaged, 100ft storage silos threatened to weaken the towering structures.

Seventeen workers remained hospitalised on Sunday in critical conditions with severe burns.

"Currently, we are focusing our efforts on working with authorities on the continued rescue effort, providing all available support to those receiving medical attention as well as the families of those co-workers who have been affected," said John Sheptor, president and CEO of Imperial Sugar.

"With the facility still under the authority of the fire department's rescue team, we are unable to provide specific information about the cause of this tragedy or any other detail."

Imperial Sugar was one of the largest and oldest employers in the city. The refinery was a network of warehouses, silos and buildings eight stories tall connected by corridors of sheet metal.