A huge armed police presence is outside a seafront hotel in Bognor Regis.
Armed officers have been pictured in the vicinity of the Royal Norfolk Hotel on The Esplanade.
The 'ongoing incident' in West Sussex involves a man in distress, police said.
Both uniformed and officers in plain clothes were seen in the area this morning.
An section of the seafront has been cordoned off and a drone is being used to survey the scene, the Argus reports.
Witnesses have reported a large number of police cars and vans parked in streets close by.
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A spokesman for Sussex Police told the Bognor Regis Observer: "Police are currently dealing with an ongoing incident involving a man in distress in The Esplanade, Bognor Regis.
"We have no further information at this stage."
Mirror Online has contacted Sussex Police for further comment.
The force has urged residents living nearby to continue to follow social distancing guidelines and the Government's stay at home advice, despite the disturbance.
Superintendent Justin Burtenshaw said: "I'd like to thank everyone for their patience and understanding as we continue to respond to this ongoing incident.
"Please continue to adhere to the government's guidelines on social distancing, and avoid The Esplanade in particular.
"Due to the nature of the incident, the public can expect to see a heightened police presence in the area.
"This is an isolated incident contained to one property, and we have no information at this stage to suggest anyone else is inside, or that there is any threat to the wider community."
We'll be bringing you the very latest updates, pictures and video on this breaking news story.
