The number of fatalities increased after the Kansas Highway Patrol reported eight people died in a highway pileup caused by a dust storm in Sherman County Friday. At least 50 vehicles were involved.

At least 16 people have been killed in a monster storm sweeping across much of the US. Ten people were killed in Missouri after a tornado outbreak, the Missouri State Highway patrol said. The agency said multiple people were also injured.

The meteorological agency said: "If you live in these areas, get to the sturdiest structure you have access to and remain in place until the storms pass." Mike Kehoe, governor of Missouri - where the 11 deaths were reported across four south-easterly counties - said the state had been "devastated by severe storms and tornadoes,