Police and forensics officers sealed off a chemist's after a man suffered head injuries.
A police car was parked at The Hill in Northfleet, after the alleged attack this morning.
Police were called at 11.46pm last night amid concerns for a man said to have been found with a head injury.
He was taken to hospital where he remains in a serious condition.
A poster on Facebook said they had seen a rucksack with blood on it nearby.
A forensics vehicle was at the site of the Hill Pharmacy, and two police officers stood guard.
Police cordoned off a section of the street.
A 39-year-old man from Gravesham was arrested on suspicion of assault and has now been released on bail until September 4.
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