KANSAS CITY, Mo. -- Thunderstorms and tornadoes tore across the nation's heartland yesterday evening. At least 11 people were killed in a storm that mangled buildings and trapped people in the rubble of their homes in areas still reeling from other recent bouts with severe weather.

A twister killed at least six people in the northeastern Oklahoma town of Picher yesterday and left widespread destruction, authorities said.

The death toll could go higher, said Oklahoma Emergency Management spokeswoman Michelann Ooten. The tornado caused major damage in a 20block area, she said.

"I know they are going through the rubble, trying to find people missing," she said. "There are numerous injuries."

First responders were working to free people trapped in the rubble, the department said.

At least five people died in southwestern Missouri after the storms plowed through, the National Weather Service said. Three people died after a tornado hit near Seneca in Newton County, said meteorologist Bill Davis.

Other tornadoes were reported near McAlester and Haywood in Pittsburg County and in rural Pushmataha County, both in southeastern Oklahoma.

In Arkansas, a tornado damaged buildings and pulled down trees in Stuttgart. The weather service said that trees were down across a wide area of the southeast Arkansas city and that an elderly woman was reported trapped in her home. The storms remained active last night, with watches and warnings abundant across a wide swath of the Plains and South.

Tornadoes killed 13 people on Feb. 5, and seven more were killed in an outbreak on May 2. In between, freezing weather, persistent rain and river flooding damaged residences and have slowed farmers in their planting.