At least six people have been killed and many injured after tornadoes ripped through the Dallas-Fort Worth area in Texas, destroying homes and uprooting trees, authorities in the US state have said.

Roger Deeds, Hood County Sheriff, said the death toll could rise as rescue workers combed through houses in the middle of the night, hampered by darkness that kept them from seeing the full extent of the devastation.

At least three tornadoes were confirmed to have struck north-central Texas on Wednesday night, with the most severe damage in Granbury, a town about 56km southwest of Fort Worth, particularly in two neighbourhoods of single family homes on the fringe of the city.

All six of the people confirmed killed were found in or around houses in the Rancho Brazos neighbourhood, Deeds said.

"At this point, right before I came out here, I've got 14 people that are unaccounted for," he said.

"I had three different storms that came through but this is the worst one."

Matt Zavadsky, a spokesman for MedStar Mobile Healthcare, an agency that provides ambulance service to the region, said about 100 people were injured in the tornado.

There was no immediate estimate for the extent of property damage, but Sheriff's Lieutenant Kathy Jividen said a number of homes were destroyed and trees toppled.

"We're going house to house right now," she said.

In Granbury, Pastor Dean Porter of Lake Granbury Christian Temple said that looking out the front porch of his church at the parking lot he began to see "what looked to be a circular formation" and he ran back inside.

Properties were damaged but no one was injured in nearby Parker County, bordering Hood County, Parker County Judge Mark Riley said.

The US tornado season typically starts in the Gulf Coast states in the late winter, and then moves north with the warming weather, peaking around May and trailing off by July.