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Emergency services were seen at the bottom of Chatham Hill this afternoon.
Kent air ambulance were called to the scene at 1.02pm to a crash involving a motorbike.
A local business worker in the High Street said the incident happened underneath one of the smaller arches about an hour ago.
She said: "I looked out to see a lot of flashing blue lights and ambulances. There were lots of people there taking pictures.
She added police cars remained at the scene now.
Fire crews were called at 1:05pm to assist police and paramedics at the scene.
Police spokesman, Jordan Bluer, said: "We were called at 12.46pm on Thursday 16 November to a collision between a car and a motorbike in Luton Road, Chatham.
"Officers are currently at the scene alongside the South East Coast Ambulance Service. The motorcyclist has been taken to a London by air ambulance hospital for treatment."