|The state of Missouri has declared a state of emergency after at least three died in tornadoes there [Reuters]
At least 11 people have died from a series of tornadoes caused by a massive winter storm in the midwestern United States.
According to the national weather service, some 30 tornadoes have affected six states since Tuesday.
Homes were smashed to bits, cars were tossed into lakes, trees were uprooted and shops were reduced to rubble in towns from Nebraska to Kentucky as the powerful system whipped up strong winds, hail and ominous funnel clouds.
Now heading further east, a storm on Wednesday led to a deadly twister in the Illinois town of Harrisburg in the early morning hours.
"We've got homes toppled, cars thrown in lakes. You can't imagine how devastating it is until you're there," town mayor, Eric Gregg said.
Rescue crews were digging through the rubble in a search for survivors. Gregg said he hoped the toll in his town of 9,000 people did not rise above the six already recovered bodies.
"In small communities it's just heart breaking - we all know each other, we all care very much about each other" he said of the at least 100 injured and the damage done to 300 homes and 25 businesses, some completely destroyed by winds of up to 270km per hour.
"We're basically out there pulling - going, you know, piece by piece, pulling material off of the top of each other to try to make sure we're not missing anyone," Gregg said.
A local hospital saw one of its walls ripped off by the cyclone, but was able to avoid serious injury to patients due to an early warning to relocate anyone near the building's windows.
The initial impact of the storms hit Nebraska and neighbouring Kansas before moving eastward towards Missouri, Illinois, Indiana and Kentucky.
Severe thunderstorms pounded the states of Alabama, Georgia, Kentucky, Mississippi, North Carolina and Tennessee on Wednesday before the storm moved to the country's eastern coast.
"We're ... pulling material off of the top of each other to try to make sure we're not missing anyone"
- Harrisburg Mayor, Erin Gregg
"It's a very large storm," said Corey Mead, lead forecaster for the weather service's storm prediction center.
"There have been a number of tornado reports in addition to damaging winds and hail. We're expecting that threat to continue into today and tonight" Mead said on Wednesday.
The governor of Illinois activated the state's emergency operations system and visited Harrisburg to tour the damage.
"Our hearts go out to their families and the many others who were injured or suffered a devastating loss," Governor Pat Quinn said.
Missouri's governor also declared a state of emergency after at least three people were killed by tornadoes which ripped across the southern portion of the state, causing extensive damage in the towns of Branson, Buffalo, Cassville, Lebanon and Oak Ridge.
"As we did throughout 2011's numerous emergencies, the state of Missouri will assist at every stage of this response to keep Missouri families safe and help communities recover and rebuild," Governor Jay Nixon said in a statement.
Another two people were killed in eastern Tennessee, and a third person was feared dead, state emergency officials said.
One person was critically injured in Waubunsee, Kansas on Tuesday, the weather service said, updating an earlier report of a fatality there.
The deadly storm marks an early start to tornado season in a region still recovering from record-breaking severe weather outbreaks.
Some 545 people were killed by tornadoes in 2011, which was the deadliest tornado season since 1936 and the third worst on record, according to the national weather service.
Some 95 tornados struck the US in January, causing just two fatalities, the weather service said.