A victim is still outstanding after armed police swarmed Roman Way last night, 11 April.
Police were called at around 8.40pm on 10 April but by the time officers arrived, all parties had left.
Multiple people were reported fighting, but no one was found at the scene.
A man in his 50s from Plymouth was later arrested on suspicion of affray and remains in custody.
Forensic officers in full protective clothing arrived late on Thursday and were at the scene for several hours, working through the night and into Friday morning.
The road was sealed off for much of the evening, with police searching for evidence and speaking with residents.
The cordon has now been lifted. Officers say there is no wider risk to the public, though patrols will remain visible in the area.
A spokesperson for Devon and Cornwall Police told Plymouth Plus:
"We are appealing for witnesses and footage following an incident of violent disorder in Plymouth.
"We were called at around 8.40pm on Thursday 10 April following a report of an ongoing fight involving a number of people in Roman Way, Plymouth.
"Officers attended but all parties had left the scene. No victim was located.
"A man in his 50s, from Plymouth, was later found at an address elsewhere in Plymouth and arrested on suspicion of affray. He remains in police custody at this time.
"A scene guard was put in place but later removed. There is no wider threat to the public, but officers will continue to carry out patrols in the area.
"Anybody who witnessed the incident or has relevant CCTV, doorbell or dashcam footage is asked to contact us on 101 or via our website quoting log 774 of 10 April."
Sign up for free below to get notified with all the latest breaking news from Plymouth Plus.
