The PSNI have warned members of the public not to obstruct police after a woman was arrested and knife seized in Derry on Friday afternoon.
Police said the incident in the city centre involved possession of a knife and that an arrest was "absolutely necessary" to protect the public.
A woman was taken into custody about "possession of a knife along with other offences," the PSNI said.
"During the arrest, members of the public approached police and tried to become involved," a spokesperson indicated.
"Can we remind members of the public not to interfere when police are dealing with incidents?
"Yes, it’s understandably distressing for members of the public to see these kind of incidents but it’s also distressing for police when children are present. We ask this for your own safety," the PSNI said.
The force said the incident "involved possession of a knife and an arrest was absolutely necessary to protect you, the community".
The spokesperson added: "Thankfully no-one was injured during this incident, apart from a police officer who was kicked."