West Virginia floods have killed at least 20 people, including an eight-year-old boy and a toddler, according to state officials.

Heavy storms and flooding have caused widespread damage throughout the state, said Governor Earl Ray Tomblin.

A state of emergency was declared in 44 of the state’s 55 counties.

Rescue teams are helping about 500 people trapped in a shopping centre while officials continued to search for others stranded in devastated areas.

The flooding has destroyed more than 100 homes and knocked out power for thousands after a storm system dumped nine inches of rain on parts of the state.

Governor Earl Ray Tomblin said 200 National Guard soldiers were carrying out search and rescue efforts as well as health and welfare checks in eight counties across the state.

A church pastor told the AP news agency an eight-year-old boy slipped, fell into a creek and was swept away.

The boy’s mother attempted to save him but lost her grip on the child, according to Harry Croft, pastor at Marwin Church of the Nazarene at Wheeling.

The child’s body was found about a half-mile from where the family lives.

The body of a 4-year-old boy was also recovered a day after the child slipped into a creek swollen with flood waters.

Ravenswood Fire Department official Bob Bibbee said the toddler was with his grandfather when he fell into the water in Jackson County.

The grandfather jumped into the creek to try and save the boy, but was overcome by the rushing water.

Governor Earl Ray Tomblin called the flooding “among the worst in a century for some parts of the state”.