A number of tornadoes ripped through parts of the U.S. Midwest on Tuesday, even as the city of Joplin, Miss., struggled to recover from the deadliest tornado to strike the United States in more than 60 years.

Oklahoma Gov. Mary Fallin told CNN that the state was hit by at least four tornadoes. Authorities said at least four people were killed after a tornado touched down in an Oklahoma City suburb. It was not clear how they died. Another woman died at a mobile home park in Oklahoma.

Three children were in critical condition after the storms hit, and search dogs were called out to search for victims in Canton.

The storms began about 3 p.m. in western Oklahoma. One of the tornadoes that was on the ground swept through thetowns of El Reno and Piedmont in the western and northern Oklahoma City suburbs.

Emergency workers told the Associated Press that a number of people were injured at Piedmont, a small community northwest of downtown Oklahoma City.

In Kansas, police said two people died when high winds threw a tree into their van around 6 p.m. near the small town of St. John, about 150 kilometres west of Wichita. The highway was shut down because of storm damage.

One person was reported dead early Wednesday after a twister hit the Arkansas community of Denning.

On Sunday, a single twister in Joplin killed at least 122 people. More than 750 were injured. That's the highest toll from one tornado since accurate record-keeping began, surpassing the 116 people who were killed in a single