Two young children have died after strong winds toppled a tree onto the back of their family’s moving car, authorities said.

The 8-year-old and 3-year-old were killed in Lufkin, east Texas on Saturday as powerful storms continued to move across southern states in the US – reportedly killing at least four people in total.

The parents, who were in the car’s front seats, were not injured, according to the Angelina County Sheriff’s Office, but the children were pronounced dead at the scene.

One person was killed in north-eastern Mississippi on Sunday when a tree crashed onto his trailer after a tornado struck the area, said Monroe County road manager Sonny Clay.

Another 19 people in the county were taken to hospitals, including two who were in critical condition.

Tornado tears through Alabama killing 23 Show all 15 1 /15 Tornado tears through Alabama killing 23 Tornado tears through Alabama killing 23 Tornado in Dothan, Alabama on March 3 AFP/Getty Tornado tears through Alabama killing 23 Debris and a damaged house following a tornado in Beauregard, Alabama on March 3 Scott Fillmer/Reuters Tornado tears through Alabama killing 23 People walk amid debris in Lee County, Alabama AP Tornado tears through Alabama killing 23 Damage in Lee County, Alabama AP Tornado tears through Alabama killing 23 A funnel shaped cloud on the I-10 near Marianna, Florida on March 3. Tornado warnings have been issued across the southeast of the US AP Tornado tears through Alabama killing 23 House debris following a tornado in Beauregard, Alabama on March 3 Scott Fillmer/Reuters Tornado tears through Alabama killing 23 A tornado in the distance at Warner Robins, Georgia on March 3 @KEITH_IRWIN/Reuters Tornado tears through Alabama killing 23 A fallen pylon lies across Route 280 in Lee County, Alabama AP Tornado tears through Alabama killing 23 Fallen trees lie across a road following a tornado in Beauregard, Alabama on March 3 Scott Fillmer/Reuters Tornado tears through Alabama killing 23 Damaged trees seen following a tornado in Beauregard, Alabama on March 3 Scott Fillmer/Reuters Tornado tears through Alabama killing 23 People look on at clean-up efforts following a tornado in Beauregard, Alabama on March 3 Scott Fillmer/Reuters Tornado tears through Alabama killing 23 People clear fallen trees and debris from a road following a tornado in Beauregard, Alabama on March 3 Scott Fillmer/Reuters Tornado tears through Alabama killing 23 Fallen trees following a tornado in Beauregard, Alabama on March 3 Scott Fillmer/Reuters Tornado tears through Alabama killing 23 Tornado in Dothan, Alabama on March 3 AFP/Getty Tornado tears through Alabama killing 23 Emergency responders work in the scene amid debris in Lee County, Alabama AP

A tornado with peak wind speeds of 140 mph was also recorded in Robertson County in Texas on Saturday.

County sheriff Gerald Yezak told the Associated Press that the tornado hit the small central Texas city of Franklin, overturning mobile homes and damaging other residences.

Two people were hospitalised with injuries which were not thought to be life-threatening, while other people were treated for minor injuries at the scene, Mr Yezak said.

The storm which led to the two children’s death in Lufkin, east Texas, was a separate incident to the tornado in Franklin.

Other tornadoes were reported in both Mississippi and Tennessee. National Weather Service meteorologist John Moore said a possible twister touched down Saturday in Vicksburg, Mississippi. No injuries were reported there, but officials said several businesses and vehicles were damaged.

At Mississippi State University, 21,000 students were forced to huddle in basements and hallways as a tornado came close to the school’s campus in Starkville.

University spokesperson Sid Salter said some debris was found on campus but no injuries were reported and no buildings had been damaged.

More than 100 million people from the middle of the US to the east coast remain at risk of extreme weather, facing warnings of heavy thunderstorms and another round of tornadoes, said meteorologist Bob Oravec of the National Weather Service’s Weather Prediction Centre.

“So much of the eastern United States faces the risk of severe weather today, and that includes major cities,” Mr Oravec said.

The storm system is expected to move into Georgia later on Sunday, which has prompted officials at The Masters golf tournament to bring forward start times for the final round at Augusta National Golf Club.

Officials hope to avoid heavy rain and strong winds brought by the storms.