Victims were on the roads

The tornadoes hit during the Friday evening rush hour and many of those hurt or killed were on the roadways.

Among the dead were a woman and her baby who were traveling on Interstate 40, just west of Oklahoma City, when their vehicle was picked up by the storm and they were sucked out of it, said Betsy Randolph, spokeswoman for the Oklahoma Highway Patrol.

One tornado rampaged down the interstate, tipping over trucks and hurling hay bales, a witness said. Television images showed downed power lines, tossed cars and motorists stranded in flood water.

Mikie Hooper of Tuttle, Oklahoma, collects her belongings from her RV which was destroyed by a tornado in El Reno, Oklahoma, June 1, 2013. [Photo/Agencies]

"For reasons that are not clear to me, more people took to the roads, more than we expected. Everyone acted differently in this storm, and as a result, it created an extremely dangerous situation," said Oklahoma City Mayor Mick Cornett.

"I think we are still a little shaken by what happened in Moore. We are still burying children and victims, so our emotions are still strong," he added.

Brandi Vanalphen, 30, was among the hundreds of drivers trapped on traffic-snarled roads as she attempted to flee the tornado system menacing the suburb of Norman.

"What got me scared was being stuck in traffic with sirens going off," she said. "I started seeing power flashes to the north, and I said 'screw this.' I started driving on the shoulder. People started driving over the grass."

Moore had limited damage from the latest storm, said a police dispatcher for the city.

Sheet metal is pictured stuck in a tree along Route 66 in El Reno, Oklahoma, June 1, 2013. [Photo/Agencies]

Elsewhere, homes were destroyed, roofs were torn off and power lines were ripped down. Work crews were repairing washed-out patches of roadways and removing downed trees in order to allow aid workers to get through.

Storms also swept into neighboring Missouri, where violent winds flipped over semi-trailer trucks on Interstate 70 between St. Louis and St. Charles County to the west, said Brett Lord-Castillo, spokesman for the St. Louis County Emergency Management Agency.

Hollywood Casino St. Louis was evacuated when part of its roof was blown off, Lord-Castillo said. No deaths or serious injuries were reported in the greater St. Louis area.

Power utilities Oklahoma Gas and Electric and Ameren said 200,000 customers were without power in Oklahoma, Missouri and Illinois.

On Thursday, storms in Oklahoma and Arkansas killed at least three people, including Scott County, Arkansas, Sheriff Cody Carpenter, whose body was recovered early on Friday, said a spokesman for the Arkansas Game and Fish Commission.

A game warden was still missing on Saturday after attempting a water rescue on Thursday in Scott County, which got more than 2.5 inches (6.3 cm) of rain in two hours.

A man also died in Tull, Arkansas, when a tree fell on his car, and a woman's body was found in flood waters in Scott County on Friday.