Rescue teams searching a stretch of the River Thames in Oxford after a teenage boy fell off his bike into the river have called off their hunt.
The emergency services, including a rescue boat, firefighters and a helicopter, were called to the scene by Walton Well Road at 1704 GMT.
A helicopter with heat-seeking equipment was called in to try and find the missing 15-year-old.
A police spokesman said the search would resume early on Monday morning.
Earlier the police said the river was "swollen" and members of the boy's family were thought to be at the scene.
The Thames Valley Police spokesman said: "We are extremely concerned and conditions are treacherous.
"There is not much more we can do tonight."
He said officers would re-evaluate the scale of the search and whether to use the force helicopter again when the search resumes.
Ambulance and fire crews assisted police with the search after the youngster fell into the river in the Port Meadow Marina area.
The search was called off at 1950GMT.