Washington, May 27 (IANS/DPA): Powerful storms have caused extensive damage in the southern and midwestern regions of the United States, with at least 15 lives lost.

Rescue workers and police searched for victims in the rubble and treated dozens of injured people. Deaths were reported in Texas, Arkansas, Oklahoma, and Kentucky, according to US media on Sunday.

Tornadoes were reported in many places overnight on Saturday. US media reported hailstones that were about the size of tennis balls.

According to initial estimates, one of the storms in Oklahoma reached at least level three out of five. Tornadoes of this classification can reach speeds of up to 265 kilometres per hour.

According to CNN, almost 5,00,000 people in nine US states were without power on Sunday evening. A state of emergency was declared in several regions.

Cooke County, near Dallas, was hit hard by winds that destroyed a motorway service area and ravaged a trailer park, resulting in the deaths of seven people, including four children, according to the sheriff.

More than 100 people were injured, and hundreds of houses were destroyed throughout Texas, said Greg Abbott, the state's governor.

Experts attribute the rise in natural disasters in the US - such as storms, floods, and forest fires - to the impacts of climate change.

According to the US National Weather Service, the frequency of tornadoes has increased in recent years.