At least 10 people,including three children were killed and a dozen others injured when a tornado tore through the US state of Mississippi. Roofs were torn off,homes were splintered,vehicles were overturned and roads were blocked by toppled trees. Mississippi Governor Haley Barbour called the twister "gigantic" that struck the region yesterday and said "in places it seemed to be several miles wide as some residents were trapped in badly damaged homes". Greg Flynn,a spokesman for the Mississippi Emergency Management Agency,said five people were killed in Choctaw county,including two children. Four victims were in Yazoo county and one was in Holmes county. The death toll is expected to rise as rescue crews reach hard-hit areas where structures have been badly damaged,Flynn was quoted as saying by the CNN. President Barack Obama has been briefed on the tragedy in Mississipi and the situation is being followed by the White House,Obama's spokesman Bill Burton said. Tornadoes were also reported in Louisiana,Arkansas and Alabama,and the severe weather continued to move eastward.