Police have confirmed they were searching Gabalfa on Thursday afternoon following reports of a 'man with a knife'.
Aberporth Road in Gabalfa was closed in both directions from the mini-roundabout to the junction of Waterston Road.
There was a large police presence on the road with eight police vehicles parked in the area.
Officers searched a house near the junction of Aberporth Road with Waterston Road.
Front gardens on Waterston Road were also searched and officers spoke to residents.
South Wales Police has confirmed officers are now investigating following the incident which took place on Thursday afternoon.
A spokesman for South Wales Police said: "At around 4.40pm, police were called to reports of a man with a knife at a disturbance involving a group of males in Aberporth Road.
"A 17-year-old and a 18-year-old sustained non-life-threatening injuries.
"The 17-year-old, who is from Rhiwbina, has been arrested on suspicion of affray and enquiries are continuing."
Officers have now searched the area and a knife has been recovered.
Anyone who witnessed the incident, or who has any information, is still being urged to contact South Wales Police on 101.
Alternatively, you can also contact Crimestoppers anonymously on 0800 555 111 quoting occurrence number 1900242209.
