Tornado watch as strong US storm hits Plains

A crowd of onlookers take photographs of the rising level of the Ohio River as it encroaches the barrier wall at Smothers Park in Owensboro, Kentucky. Photo / AP

A tornado watch was issued in parts of four US states as a strong storm system moved into the South and Plains states.

The watch was in effect in most of Arkansas and in northeastern Texas, southeastern Oklahoma and northeastern Louisiana.

The weather service said the system was also capable of producing wind gusts of up to 120 km per hour and hail about the size of an egg.

Heavy rain and flooding is also possible and a levee breach along the Kankakee River in northwestern Indiana has local officials urging about 30 homeowners to evacuate.

Keener Township Volunteer Fire Chief Randy Woods says the breach was relatively minor when it was discovered near Demotte, about 80km southeast of Chicago.

He says local residents tried to sandbag the breach "to get it under control, but it just got bigger and bigger."

Local firefighters were called to help them, but eventually everyone had to pull out for their own safety. No injuries were reported.

The National Weather Service says record flooding was occurring along the Kankakee following several days of heavy rains and snowmelt that have sent streams out of their banks from the Ohio River to Michigan and Wisconsin.

-AP