Residents were unable to assess the damage until daylight

Power lines were knocked out and homes destroyed in Anna and Westminster, about 40 miles (65km) north of Dallas.

Neighbouring Oklahoma was also hit but no injuries were immediately reported, although there was some flooding.

Utility workers are assessing the damage caused and work has begun to restore power to the homes affected.

Rise in tornadoes

The tornadoes struck just before midnight on Tuesday.

Authorities have not released the identities of the dead, but said they included an elderly couple and a teenager.

The American Red Cross has opened a shelter at a high school in Anna.

The latest storm comes after 12 people died in April when tornadoes and severe storms swept across the state of Tennessee.

The number of tornadoes in the US has risen dramatically in the first part of 2006, according to the National Weather Service's Storm Prediction Centre.

At the end of March, an estimated 286 tornadoes had hit the US, against an average of 70 for the same three-month period over the past three years.