A five-year-old child was killed and at least 19 other people injured when a powerful storm with tornadoes ripped through north-east Nebraska, hospital and emergency officials said.

More than half of the tiny town of Pilger was destroyed.

The National Weather Service said dual twisters touched down within roughly 1.6km of each other.

Emergency crews and residents spent the evening sorting through demolished homes and businesses in the community of about 350 people, roughly 160km north-west of Omaha.

"More than half of the town is gone - absolutely gone," said Stanton County Commissioner Jerry Weatherholt. "The co-op is gone, the grain bins are gone, and it looks like almost every house in town has some damage. It's a complete mess."

Victims were taken to three regional hospitals, and at least one died from unspecified injuries, hospital officials said.

Jodi Richey, a spokeswoman for Faith Regional Health Services in nearby Norfolk, said one person died and 16 others were being treated at the hospital. Hospital officials initially described those patients as being in a critical condition, but said later that some had been released after treatment.

Stanton County Sheriff's Office confirmed that the person killed was a five-year-old child.

One casualty was transferred to a trauma centre in Omaha, while others required surgery, said Dr Doug Dilly, who was in the emergency room when patients arrived.

Providence Medical Centre in nearby Wayne treated three tornado patients, including two who had lacerations, said hospital spokeswoman Sandy Bartling. Two were later released, and the third was in stable condition, she said.

Stanton County Sheriff Mike Unger estimated that 50% to 75% of Pilger was heavily damaged or destroyed in the storm. The local school is likely beyond repair, he said.

"It's total devastation," he added.

Authorities said the first tornado touched down around 3.45pm local time and brought several power lines down before it flattened a farmhouse. Four people were trapped inside.

While local crews removed them from the debris, a second tornado was spotted south-west of Pilger, according to Stanton County Sheriff's Office.

Shortly afterwards, the town suffered a "direct hit" which levelled several buildings, including the Fire Department building, the sheriff's office said.

Several people near Main Street in Pilger were critically injured, including the child who later died.

Nebraska Governor Dave Heineman declared a state of emergency, and the National Guard was preparing to assist local emergency responders and help with the clean-up. Mr Heineman and officials with the Nebraska Emergency Management Agency were expected to arrive in the area later.

Pilger was evacuated for the night, and the Nebraska State Patrol closed all roads into town. Most residents made their own arrangements, but some were taken to a shelter at Wisner-Pilger Jr-Sr High School in nearby Wisner.

About a dozen residents had arrived at the makeshift shelter by 9.30pm local time and school officials were expecting more to come later, said Wisner-Pilger Schools Superintendent Chad Boyer. The shelter will remain open to residents for as long as needed to offer food, water, showers and cots, he added.

Tornadoes also caused damage in Cuming and Wayne counties, the Nebraska Emergency Management Agency (Nema) said in a news release.

"We are still in a response mode in these communities," said Earl Imler, Nema's operations officer. "We are collecting damage reports from local officials on the ground."

Officials will not know the intensity of the storms until later, after crews have examined the area, said Barbara Mayes, a meteorologist with the National Weather Service in Valley.

Ms Mayes said the dual tornadoes were unusual because both appeared to have roughly the same strength. In most cases, she said, one tornado tends to be larger and more powerful than the other, and the bigger cyclone grows stronger as the smaller one weakens.

"It's less common for two tornadoes to track together for so long, especially with that same intensity," she said. "By no means is it unprecedented. But we don't see it often."

Meteorologists with the National Weather Service also tracked a tornado near the town of Burwell, in central Nebraska. Ms Mayes said they had not received reports of damage.