Specialist police search teams have been combing the River Severn after a man was arrested on suspicion of murder.
A 24-year-old man was detained on Wednesday as part of an investigation in Worcester.
West Mercia Police have sealed off three locations, including an area around Diglis footbridge, Waterworks Road and across the city in Cheviot Close.
The force said the cordons were in response to a “serious incident” in the city.
Officers are working alongside the fire service and a specialist search team from South Wales Police, which has been scouring the river in the Diglis area.
Detective Chief Inspector Dean Jones, of West Mercia Police, said: “A 24-year-old man has been arrested on suspicion of murder and is currently in police custody.
“We believe this to be an isolated incident.”
Police asked the public to keep away from the cordoned areas while they investigate.