A storm system sweeping across Missouri has left at least three people dead, as a tornado ripped through the state capital Jefferson City late Wednesday night.

The National Weather Service issued an emergency alert shortly before 11.45pm warning city residents a “violent tornado” was about to hit the city and advised they take “shelter now!”

No fatalities have been reported in the capital, but Jefferson City Police Lieutenant David Williams said emergency services have received multiple calls of people being trapped in homes damaged after the twister struck. “It’s a chaotic situation right now,” Mr Williams said.

Missouri Department of Public Safety said there was extensive damage to the city’s infrastructure – including downed power lines.

Officials have asked the Federal Emergency Management Agency (FEMA) for assistance with the search and rescue efforts, according to NBC affiliate KOMU. “The best word to describe the damage is devastating,” said Jefferson City’s mayor Carrie Tergin.

Highest threat level as tornado sweeps Oklahoma Show all 5 1 /5 Highest threat level as tornado sweeps Oklahoma Highest threat level as tornado sweeps Oklahoma A tornado spins during stormy weather in Mangum, Oklahoma Lorraine Matti / Reuters Highest threat level as tornado sweeps Oklahoma A tornado spins during stormy weather in Mangum, Oklahoma Clint Lively / Reuters Highest threat level as tornado sweeps Oklahoma The silhouette of a tornado appears during a lightning strike in Haskell, Oklahoma Matthew Harden / Reuters Highest threat level as tornado sweeps Oklahoma A tornado spins during stormy weather in Mangum, Oklahoma Lorraine Matti / Reuters Highest threat level as tornado sweeps Oklahoma A tornado spins during stormy weather in Mangum, Oklahoma Lorraine Matti / Reuters

It follows three confirmed deaths in Barton County in south west Missouri on Wednesday after a suspected tornado hit the area. A separate twister caused widespread damage in the town of Carl Junction, four miles north of Joplin airport.

Wednesday marked the third consecutive day of dangerous storms, torrential rains and tornado warnings across the Midwest, mostly in Missouri and Oklahoma.

In eastern Oklahoma, two barges broke loose and floated swiftly down the swollen Arkansas River, spreading alarm downstream. Officials in Webbers Falls ordered a mandatory evacuation Wednesday afternoon.

A posting on the town’s official Facebook page sounded the alarm about the runaway barges: “Evacuate Webbers Falls immediately. The barges are loose and has the potential to hit the lock and dam 16. If the dam breaks, it will be catastrophic!! Leave now!!”

Deaths from this week’s storms include a 74-year-old woman found early Wednesday morning in Iowa. Officials there say she was killed by a possible tornado that damaged a farmstead in Adair County.

Another weather-related death may have occurred in Oklahoma, where the Highway Patrol said a woman appeared to have drowned while driving around a barricade near Perkins, about 45 miles northeast of Oklahoma City. The unidentified woman’s body was sent to the state medical examiner’s office to confirm the cause of death.