Police are appealing for witnesses after an incident near Victoria Park in Worthing.
A report was made where a man was alleged to be seen with a sword at about 2.30pm on Monday September 26.
Armed officers attended the scene and arrested a 19-year-old man from Worthing on suspicion of affray. He was taken into custody, where he remains.
Anyone who was in the area, and has any relevant information, is asked to report it to police online, or by calling 101, quoting serial 691 of 26/09.