ABC News says it has confirmed 10 people have been killed in the Monday afternoon tornado.
Hospitals in the area say they treating nearly 60 injured, including more than a dozen kids, after Oklahoma tornado. ABC News says at least 10 of those injured are critical, and another 10 are serious.
Gary Knight with the Oklahoma City Police Department says there is no word of injuries from the elementary school. Knight says the school suffered "extensive damage" on Monday afternoon.
Neighborhoods in Moore, Okla., are flattened and buildings are on fire. Television footage on Monday afternoon showed homes and buildings that had been reduced to rubble in the city south of Oklahoma City. Footage also showed vehicles littering roadways south and southwest of Oklahoma City.
An Associated Press photographer saw several children being pulled out of what was left of the Plaza Towers Elementary School in Moore, Okla., on Monday after a massive tornado hit the region.
Rescue workers lifted children from the rubble before they were passed down a human chain and taken to a triage center set up in the school's parking lot.
The school is southwest of Oklahoma City. Its roof appears mangled and the walls had fallen in or had collapsed.
The National Weather Service said the tornado's preliminary classification was an EF-4, with winds up to 200 mph.
The suburb of Moore was hit hard by a tornado in 1999. The storm had the highest winds ever recorded near the earth's surface.
Winds of up to 200 miles per hour
The National Weather Service says the tornado that hit Moore, Okla., had wind speeds up to 200 mph.
The weather service's preliminary classification of Monday afternoon's tornado was an EF-4 on the enhanced Fujita scale.
Authorities say emergency crews are working to rescue people trapped in Moore, which is southwest of Oklahoma City, and officials tell ABC News the National Guard has been activated.
Television video showed debris from homes and businesses being carried aloft as the twister rolled through Moore.
There were no immediate reports of injuries or deaths, but the storm laid waste to scores of buildings in Moore, south of the city. Block after block of the community lay in ruins, with heaps of debris piled up where homes used to be. Cars and trucks were left crumpled on the roadside.
Volunteers and first responders were searching through debris looking for survivors. Television footage showed first-responders picking through rubble and twisted metal.
Oklahoma City Police Capt. Dexter Nelson said downed power lines and open gas lines posed a risk in the aftermath of the system.
The storm seemed to blow neighborhoods apart instantly, scattering shards of wood and pieces of insulation across the scarred landscape.
The same suburb was hit hard by a tornado in 1999. That storm had the highest winds ever recorded near the earth's surface.
In advance of the storm, the Oklahoma House of Representatives stopped work so Capitol employees could take shelter in the basement. Television and radio broadcasters urged residents to take shelter because the storm's strength and size.
"We're just waiting to see what happens. It's a mile-wide tornado. It's still grinding out," said Mark Meyers, a spokesman for the Oklahoma County Sheriff's Office. "We are currently on standby for tornado response. Whatever happens, we'll be ready to respond."
The strongest winds on earth -- 302 mph -- were recorded near Moore during a tornado May 3, 1999.
The Storm Prediction Center in Norman had predicted a major outbreak of severe weather Monday in Arkansas, Kansas, Missouri and Oklahoma.
Storms on Sunday killed two people near Shawnee, about 35 miles southeast of Oklahoma City. Gov. Mary Fallin earlier Monday took a tour of the areas hardest hit and she expressed concern that, with power out, Oklahomans might not receive warnings about the new round of storms.
Pottawatomie County Sheriff Mike Booth said a 79-year-old man, who was later identified as Glen Irish, was found dead Sunday out in the open at Steelman Estates, a mobile home park near Shawnee. The state medical examiner's office said Monday that a 76-year-old man, Billy Hutchinson, was found dead in a vehicle.
The office said both men lived in Shawnee, but the city wasn't hit by the tornado and it wasn't immediately clear if either or both lived in the mobile home park, which is near the city.
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