A third day of widespread flooding across Missouri left vehicles, homes and businesses completely underwater. Some small aircraft were even spotted by aerial television stations at a small airport floating on the water.

Missouri, Illinois, Arkansas and eastern Oklahoma braced for even more flooding as rain-swollen rivers, some at record heights, overflowed their banks, washing out hundreds of structures, closing major highways and leaving thousands of people displaced from their homes.

Days of downpours from a winter storm that set off deadly tornadoes in Texas and significant snowfall in New England has pushed rivers in the US Midwest to levels not seen in decades, the National Weather Service and local officials said.

The flood has closed sections of Interstate 44 and Interstate 55, both major trucking routes, along with many local roads near rivers.

Freezing temperatures in the area in the coming days will cause some flooded areas in Missouri and Illinois to turn icy, adding to challenges, forecasters said.

At least 27 people have died in the region's flooding since the weekend, mostly from driving into flooded areas after storms dropped up to 30 cm of rain.