OKLAHOMA CITY, Okla. — Violent thunderstorms spawned tornadoes that menaced Oklahoma City and its already hard-hit suburb of Moore on Friday, killing a mother and her baby, and officials worried that drivers stuck on freeways could be trapped in the path of dangerous twisters.

The mother and her baby were killed while traveling on Interstate 40, just west of Oklahoma City, when their vehicle was picked up by the storm, said Betsy Randolph, spokeswoman for the Oklahoma Highway Patrol. The interstate was shut down due to the storm, with multiple crashes and injuries.

National Weather Service meteorologists at one point declared a tornado emergency for parts of the Oklahoma City metropolitan area, including Moore, and storm spotters were tracking a tornado in the western suburb of Yukon. One twister touched down on Interstate 40 and was headed toward Oklahoma City.

A tornado also touched down in Moore, which was hit by a massive EF-5 twister last week that killed 24 people.

“The Interstate is at a standstill,” Randolph said. “We are begging people to get off the Interstate and seek immediate shelter … We are in a dire situation.”

Oklahoma Governor Mary Fallin told CNN that motorists stuck on any freeway in the path of a twister should try to go in the opposite direction to where the twister was coming from.

“What we saw from the tornadoes that came through Moore and the other ones last week was that people who were in cars on the Interstate were killed,” Fallin told CNN. Moore Mayor Glenn Lewis told CNN it was “unbelievable” that Moore had been hit again.

Tim Oram, meteorologist for the National Weather Service, said it was difficult to know exactly how many tornadoes had touched down, but three major storms were potentially producing tornadoes throughout the center of the state.

MULTIPLE STORMS

At a little after 8 p.m. local time, two of the storms were passing through Oklahoma City’s southeastern suburbs, including Moore, he said. Those two storms were headed toward Norman, with the other storm southwest of the Oklahoma City.

Will Rogers Airport in Oklahoma City was shut down as it sheltered 1,200 people, local station KWTV reported. Oklahoma Gas and Electric Company reported that 53,000 customers in the Oklahoma City area were without power.

Storms in Oklahoma and Arkansas on Thursday left an Arkansas county sheriff dead and at least one man missing in an attempted water rescue, while at least seven other people were injured elsewhere, officials said. The body of Scott County Sheriff Cody Carpenter was recovered early on Friday, said Keith Stephens, a spokesman for the Arkansas Game and Fish Commission.

Authorities continued to search for a missing state game warden after Thursday night’s rescue attempt along the Fourche La Fave River.

A man died in Tull, Arkansas, when a tree fell on his car during a possible tornado, said Grant County sheriff’s chief deputy, Pete Roberts. A Scott County official said a woman’s body was found in floodwaters on Friday.

Large, long-lasting thunderstorms known as supercells are responsible for producing the strongest tornadoes, along with large hail and other dangerous winds.

Tulsa, as well as Springfield, Mo., may all be buffeted by Friday’s severe weather and possible tornado touchdowns, said Rich Thompson, a lead forecaster at the National Weather Service’s Storm Prediction Center in Norman, Oklahoma. The danger zone included Joplin, Mo., he added. Joplin was hit by a monster tornado, one of the most catastrophic in U.S. history, that killed 161 people and destroyed about 7,500 homes two years ago.