In the hardest-hit town of Sulphur in Murray County in south Oklahoma, a person was killed and some 30 others injured in the wake of at least two large tornadoes, which flattened a number of homes and buildings, Xinhua quoted Stitt.
Two others, including an infant, died in the Holdenville city, where at least 14 homes were damaged or destroyed.
The fourth died near an interstate road, local media reported.
"In addition to the severe weather, intense rainfall rates are expected to accompany these thunderstorms at times, leading to a moderate to locally high potential of flash flooding," the National Weather Service said.
AMK/PR