At least three tornadoes have slammed several small towns in East Texas east of Dallas, and authorities believe as many as five people are dead and dozens injured, though they're still assessing the situation.

Canton Fire Department Capt. Brian Horton says the twisters that hit Saturday evening about 50 miles (80 kilometers) east of Dallas have caused "maybe five casualties" but the that number "may go up" once authorities can go through overturned vehicles and destroyed homes and other wreckage.

ETMC Regional Health Care Systems spokeswoman Rebecca Berkley says 56 people have been treated at three hospitals in the area. Six remain hospitalized Sunday morning and two of those are in critical condition.

The National Weather Service has confirmed at least three tornadoes swept through parts of three counties.