A man has been arrested on suspicion of dangerous driving following a serious collision on the A406.
The accident involving two vans and a lorry happened at around 2.30pm yesterday on the North Circular southbound between Ilford and Barking.
Emergency services including London's Air Ambulance and the London Fire Brigade attended the scene.
Two men suffering multiple injuries were removed from their vehicles by paramedics and one patient suffering from shock was given oxygen by the fire crew.
They were both taken as a priority to the Royal London Hospital in Whitechapel by land ambulance but their injuries are not deemed life-threatening, a police spokeswoman has confirmed.
The driver arrested at the scene remains in police custody.
All lanes southbound were closed for several hours for investigation and to remove the wrecked vehicles and debris.
Traffic on the A406 in both directions towards Redbridge roundabout and Beckton was solid until around 6pm with some drivers stuck in queues tailing back 10 miles.