The National Weather Service has issued a tornado emergency for the Oklahoma City metropolitan area.
A storm dropped a tornado in Oklahoma City's western suburbs, then barreled toward the state's largest city as cameras broadcast the approach on television.
Damage was reported Friday south of Interstate 40 near El Reno after the twister swept through a rural area. The Canadian County Sheriff's Office said it did not have any reports of injuries.
Funnels of various sizes touched the ground south of El Reno, 25 miles west of Oklahoma City. At other times funnel clouds remained aloft. Cameras showed debris in the air.
State police conducted rolling roadblocks to prevent motorists from driving into the storm as it approached Oklahoma City, which has a million people in the metro area.
Weather service forecaster Daryl Williams says the emergency issued Friday evening includes Oklahoma City and some suburbs. The weather service issues an emergency if a storm with tornadoes is heading toward large metropolitan area.
The warning covered Will Rogers World Airport in Oklahoma City. The airport's website says passengers have been moved to underground tunnels and no flights are arriving or departing.
Oklahoma Highway Patrol Trooper Betsey Randolph says the OHP has shut down Interstate 40 in Oklahoma City and the OHP issued a warning for motorists to exit I-40 and seek shelter.
A storm last week killed 24 at Moore, on Oklahoma City's south side.