A KFC spokesperson confirmed a “serious incident” had taken place at its Bromley High Street restaurant and that the altercation had begun there.
The firm said it was assisting police and supporting team members and customers.
Following the incident, an eyewitness dining at the branch said a fight broke out and a man wielding a machete ran from the scene.
A local business owner said she had seen a fight spill out onto the street.
The Met Police said officers were working quickly to establish the full circumstances, and there would be an increased police presence in the area.
Detectives are treating the incident as an isolated event.
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