Tornado watches were issued across a wide swath of the US Midwest on Tuesday, affecting dozens of counties in Kansas, Missouri, Iowa and Nebraska, the National Weather Service said.

The watch was issued at 1425 central time (1925 GMT) and follows a monster tornado that hit Moore, Oklahoma, killing 24 people last week.

The top-force tornado was one of the most powerful in years, damaging or destroying 1,200 homes and affecting an estimated 33,000 people, according to officials. Initial monetary damages have been estimated at around $2 billion.

President Barack Obama visited the area Sunday to offer solace and support to residents.