A man has been arrested on suspicion of attempted murder after a car plunged into a river in Evesham, leaving two young children fighting for life.
West Mercia Constabulary said a five-year-old girl and a six-year-old boy were both in a critical condition after being airlifted to hospital in Birmingham.
The younger of the children was only rescued from the submerged vehicle by police divers two hours after the emergency services were called to the scene at Boat Lane, at about 9.20am on Thursday.
A police spokesman said: "Officers were called to the scene at around 9.19am after reports a car had entered the river containing occupants.
"Emergency services, including divers, took part in a rescue operation and a man and two children were recovered from the river. The man was taken to Alexandra Hospital, Redditch, where he was treated and later discharged."
The police spokesman, who would not comment on the relationship between the man and the children, added that a man had been arrested in Evesham on suspicion of attempted murder.
West Midlands Ambulance Service said the boy and a man in the car had escaped from the water when its crews arrived, but the girl was rescued from the vehicle by police divers.
An ambulance service spokesman said: "The boy's condition was stabilised before he was airlifted to Birmingham Children's Hospital in a critical condition.
"A young girl was pulled from the submerged vehicle around two hours later by police divers. Ambulance staff immediately started resuscitation attempts and she too was airlifted to Birmingham Children's Hospital."
The incident happened on a stretch of the River Avon which is around 100ft wide and is overlooked by a caravan park.
Police cordoned off Boat Lane around 200 yards from the river, where a crane arrived at about 2.30pm. From the opposite bank of the river, more than a dozen emergency vehicles, including a fire engine, could be seen in attendance, where Boat Lane ends and a slipway runs into the water.
Superintendent Garry Higgins, of the South Worcestershire police division, said: "This was obviously a very traumatic incident - our officers are been left very shaken by events.
"All of the emergency services involved in the operation worked closely throughout to effect the rescue.
"An investigation into the incident in now ongoing and we would also like to hear from anyone who was in the area around the river at Boat Lane this morning before 9.20am."
Two ambulances, a rapid response vehicle, a specialist paramedic from the hazardous area response team and the Midlands air ambulances from Strensham and Cosford were sent to the scene.