Four police officers suffered injuries at two separate incidents in Norwich, with one having to be sent home.
Two officers were hurt at an incident to the north of the city at about 4pm this afternoon.
They, along with the ambulance service, were responding to concerns for a person's wellbeing.
At about 9pm, two further officers were injured while helping a person who had become aggressive at a night shelter in the city centre. While none suffered serious injuries, one was sent home as a precaution.
Sergeant Mark Shepherd said it had been a particularly busy night.
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