Tornadoes in Mississppi
The remains of the Beverly Chapel CME Church on old Highway 4 are seen after a tornado struck Holly Springs, Mississippi, in this National Weather Service picture taken December 24, 2015. Southern U.S. states began digging out on Thursday after severe storms including some 20 tornados killed at least 10 people and Mississippi delared a state of emergency.REUTERS/National Weather Service Memphis/Handout via Reuters

The death toll in the southeast region of the US has risen to at least 11, following a severe storm system that included powerful tornadoes. The spring-like storm system, which was aided by unseasonably warm weather, killed people across Mississippi, Tennessee and Arkansas. Dozens of others were injured by the tornadoes. Authorities said over 20 tornadoes hit Arkansas, Illinois, Indiana, Mississippi, Tennessee and Michigan on 23 December.

Mississippi experience the worst of the storms, with at least seven people dead. Four people died and one person remained unaccounted for in Benton County, according to officials. Two more people died in Marshall County and a seventh person died in Tippah County. Among those killed was a 7-year-old boy, who died while in a car with his family near Holly Springs.

Over a dozen tornadoes were reported in Mississippi. In Clarksdale, Mayor Bill Luckett told The Associated Press the severe storm had claimed the life of a dog, which was killed by storm debris. The mayor added that planes were overturned at a small airport and that it was unknown how many people were injured. "I'm looking at some horrific damage right now," Luckett said. "Sheet metal is wrapped around trees; there are overturned airplanes; a building is just destroyed."

The Mississippi Emergency Management Agency reported at least 40 people were injured by the storms. Agency spokesman Greg Flynn said that some of the injuries involved amputations, NBC News reported. Mississippi Governor Phil Bryant declared a state of emergency in the areas affected by the storms, adding that 14 tornadoes had ravaged the state.

"Everybody is pulling together here in Mississippi today to help respond to this disaster," Bryant said during an interview on CNN. According to Reuters, Bryant said shelters were set up and that the full extent of the damage would be unknown for several days.

In Tennessee, at least three people were reported dead. According to NBC News, an unidentified 22-year-old man died in Rhea County. Perry County Sherriff's Office Chief Deputy Nick Weems confirmed that 69-year-old Annie Yzaguirre and 70-year-old Antonio Gomez Yzaguirre died in Perry County. Reuters reported that thirteen counties in Tennessee suffered damages, which included a destroyed post office and a washed out state highway.

In Arkansas, 18-year-old Michaela Remus died after a tree blew over and crashed into the bedroom she shared with her 18-month-old sister in Atkins. The toddler was eventually pulled safely from the home by rescuers and taken to a hospital. Rusty Russell, a 34-year-old friend of Remus's told NBC News that the teen died protecting her younger sister. "She was laying in bed with her 18-month-old sister. The way that she was laying actually shielded her sister," he said.