Oklahoma tornado mapped
The huge tornado which tore through the suburbs of Oklahoma city has been upgraded to the most powerful type of storm.
Winds reached around 200 mph (320 km/h) and left swathes of the suburb of Moore in ruins. Officials have confirmed that 24 people have died, including seven children, and around 120 are being treated in hospital.
President Barack Obama has declared a major disaster in Oklahoma. Explore below to see videos and photos from the worst-affected areas.
The aerial view above shows the path of destruction in Moore. To explore the area in more detail, follow this link for a zoomable image.
Before and after photos
Records from the past 30 years show that tornado activity peaks in the months of May and June.