Updated 11:22 a.m. EST: Amy Elliott, chief administrative officer of the Oklahoma medical examiner's office confirmed the death count as 24, including nine children.
"Our office had reported 51 fatalities, some of those were reported possibly in error or doubled," said Elliott. She told a news conference that of the nine children found dead, seven were at a devastated primary school.
Updated 10:25 a.m. EST: Officials have announced that 24 bodies, and not the previously reported figure of 51, were recovered. The New York Times had reported early Tuesday that at least 91 had been killed.
As rescue efforts continue, these figures are likely to change again.
Updated 10:15 a.m. EST: Addressing the nation, President Obama reiterated that the devastated areas of Oklahoma would have "all the resources they need at their disposal. "Our prayers are with Oklahoma," he said, praising the bravery of first responders and specifically honoring the teachers who attempted to defend children in two Moore primary schools leveled by the twister -- "young children trying to take shelter in the safest place they knew, their school."
"As a nation, our full focus right now is on the urgent work of rescue," said the president, adding that he had signed a signed a disaster declaration for Oklahoma, clearing the way for federal aid. "There are empty spaces where there used to be living rooms, bedrooms, classrooms," he said, noting that the work will be to fill those spaces again.
Updated 10:00 a.m. EST: President Obama will be meeting with his disaster response team, including Homeland Security Secretary Janet Napolitano, on Tuesday before delivering a statement. As the AP noted, "The president also spoke Monday with Oklahoma Gov. Mary Fallin and Rep. Tom Cole, whose home is in the heavily damaged town of Moore."
The White House says Obama told Cole that the American people stand behind Oklahomans as they recover from the disaster.
Original post: According to the latest updates from the Oklahoma City medical examiner, at least 91 people have been killed by the 2-mile wide tornado which ripped through the city and suburbs, leveling everything in its path. Twenty children are among the dead as two schools were flattened by the twister. According to reports, the worst damage hit the suburb of Moore.
Reuters reports that up to 240 people, including 60 children, have been injured, going by hospital reports. The National Weather Service has said the tornado was an EF-4 on the enhanced five-point Fujita scale -- the second most powerful type of twister. President Barack Obama has declared a major disaster and ordered federal aid to supplement state and local recovery efforts. Obama is scheduled to address the nation at around 10 a.m. on Tuesday. Meanwhile the FAA has declared a no-fly zone above the disaster area to enable emergency aircraft to fly unimpeded.
Overnight, according to the local NBC affiliate, 101 people were found alive in the rubble:
The New York Times described the devastated scene in Moore late Monday night:
Plaza Towers Elementary School in Moore was reduced to a pile of twisted metal and toppled walls. Rescue workers were able to pull several children from the rubble, but on Monday evening crews were still struggling to cut through fallen beams and clear debris amid reports that dozens of students were trapped. At Briarwood Elementary School in Oklahoma City, on the border with Moore, cars were thrown through the facade and the roof was torn off.
Shortly before midnight, the area near the Plaza Towers school was eerily quiet and shrouded in darkness from a widespread power outage. Local authorities and F.B.I. agents patrolled the streets, restricting access to the school.
Half a mile from the school, the only sounds on Southwest Fourth Street were of barking dogs and tires on wet pavement littered with debris. Hovering in the sky, a helicopter shined a spotlight on the damaged neighborhoods. In the darkness, the century-old Moore Cemetery was a ghostly wreck: women’s clothing and blankets clung to the branches of tilting trees and twisted sheets of metal ripped from nearby buildings or homes were strewn among the graves. Many headstones had been pushed flat to the ground by the wind.
The full extent of the damage cannot yet be assessed. Dr Steven Godby, an expert in natural hazards at Nottingham Trent University, in the UK, told the Guardian that the financial losses from the tornado may approach that of 2011's Joplin tornado, the costliest tornado on record at $2.8bn.
Amateur video captured Monday afternoon shows the great width and vast expanses of the twister:
The terrifying footage sees the tornado pass overhead from the view of storm shelter:
BBC Weather tweeted a satellite image of the twister sweeping through the plains:
The Guardian has highlighted useful social media pages and links already set up to find missing people, pets and important possessions:
A Facebook page has been set up asking people to post any pictures or documents they have found in their yard or in the street after the tornado in the hope of reuniting them with their owners. One woman said she lives more than 100 miles away in Tulsa and found a picture of a woman in her flower bed.
There is also a dedicated site for lost and found pets as a result of the tornado.
The American Red Cross has a "safe and well" page that allows people in Moore to let friends and family know they are safe. Concerned family and friends can search the register.