A storm blamed for the death of a truck driver in Oklahoma is putting 17 million people in the central United States at risk.

The storms that struck Texas and Oklahoma late on Tuesday brought tornadoes, tennis ball-sized hail and powerful winds.

It is just the beginning of what is expected to be a stormy week in Tornado Alley and in parts of the South.

Three storm chasers also died on Tuesday in a collision as they raced towards the weather in West Texas, authorities said.

Roofs and walls were ripped away early on Wednesday from homes in Rockwall, north east of Dallas, and the city's mayor, Jim Pruitt, said one person suffered non-life-threatening injuries.

Forecasters said the storms could intensify on Thursday as the system moves past the Mississippi River.

In Oklahoma, the truck driver was killed on Tuesday night after strong winds pushed his rig off the interstate in El Reno, outside Oklahoma City.

Forecasters confirmed a 95mph wind gust in the area when the crash occurred.

In Texas, the three storm chasers - including two who were contractors for The Weather Channel - were killed in a collision at a remote intersection near the town of Spur, about 55 miles south-east of Lubbock.

The channel said in a statement that Kelley Williamson and Randy Yarnall were "beloved members of the weather community" who had worked as contractors for the channel.

The Texas Department of Public Safety said the two died on Tuesday along with another storm chaser, 25-year-old Corbin Lee Jaeger of Peoria, Arizona.

Mr Williamson and Mr Yarnall were both from Cassville, Missouri.

Department of Public Safety Sergeant John Gonzalez said a Chevrolet Suburban driven by Mr Williamson ran a stop sign and hit a Jeep driven by Mr Jaeger.

Mr Yarnall was a passenger in the Suburban. All three were killed instantly.

Tornadoes had been reported nearby at the time of the crash and heavy rain had been reported in the area.