A man approached two teenage boys in a park before pulling a knife and threatening them.
It happened at the recreation ground in Harleston between 8-9pm on Saturday, July 3.
After a verbal spat between the man, aged in his 30s or 40s, and the two teens, the man grabbed one of them and pulled a multi-tool knife before threatening him.
The two teens ran off, but the man approached them again later after two teenage girls had joined them.
They all ran off, but the man pursued one of the girls on his bike through the London Road exit.
Some people outside the JD Youngs Pub in London Road intervened and the man on the bike fled.
Police are keen to speak to the man pictured in relation with the incident.
Anyone with information should contact PC Katy Sergeant 101 quoting crime reference 36/47484/21.
Alternatively, call Crimestoppers anonymously on 0800 555 111.
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