Two boys have been electrocuted by power lines downed during violent weather in Texas, officials said.

A violent weather system that claimed 12 lives in Oklahoma and Arkansas amid tornadoes and flash floods gave way to clearing skies as the storms trekked toward the US east coast today.

A line of violent thunderstorms roared across middle America, killing six people in two states, with several tornadoes touching down in Oklahoma and high winds pounding rural Kansas.

An 87-year-old US woman who was tasered by police while hooked to an oxygen machine in her bed is suing her Oklahoma hometown.