A man in his 60s is missing and five others adults have been rescued after a rowing boat capsized on the River Thames.
Emergency services were called to Sunbury Lock, Sunbury-on-Thames, at around 8.50am on Friday, Surrey Police said.
Rescuers are still searching for the missing man, who they believe may still be in the river.
Three of the five rescued were taken to hospital for further checks, an ambulance service spokesperson said.
Efforts to establish how the boat capsized are ongoing, police said.
A force spokesperson added: “Sadly, we believe a man in his 60s may still be in the river.
“His relatives have been informed and are being kept updated.”
Chief Inspector for North Surrey, Andy Jenkins said; “This is a very distressing time for all involved and we continue to support our partners in the search for the missing man.
“Our inquires to establish the exact circumstances of how the boat capsized remain underway but at this time we do not believe there to be any suspicious circumstances or third-party involvement.
“We will look to share any further updates with you as and when we have them.”
A Surrey Fire and Rescue Service spokesperson added: “Our crews are on site, working with the coastguard, Surrey Police and other agencies.
“Five individuals were rescued, and work is ongoing to locate a sixth.”
A woman walking her dog near the river on Friday evening said she had seen a red rescue boat on the water at about 10am and there was a helicopter nearby at the same time.
The woman, who did not want to be named, said: “We could see they were searching in the water, they had walkie talkies, we could tell they were looking for something.”