Another teenager has been arrested in connection with a 'large-scale' fight at the La Mare de Carteret playing fields on Sunday evening.
Guernsey Police said around 200 young people were involved, with one person confirmed to have been taken to the Princess Elizabeth Hospital to have their injuries treated.
A 21-year-old man and a teenager were arrested at the time.
After officers broke up the initial disorder, Guernsey Police had to 'deploy additional resources to the area' as a number of smaller incidents were ongoing.
A Police spokesperson says officers are continuing to investigate what went on:
"Anyone who witnessed what happened - particularly those who may have domestic CCTV or dashcam footage of the incident itself, or the small scale incidents which occurred in the area following the police’s arrival - is asked to get in touch with the Investigation Support Unit (ISU) on 01481 222222."

Guernsey cat lover to ride the length of Britain in nine days
Unclaimed CI Co-op cash funds community projects
Work to commence on 70 affordable flats and homes in Guernsey
A new tax, more 'proportionate' to wealth, to be put to Guernsey's States
Guernsey gives £75k for Islands Unlimited inter-islands sailings
Guernsey tax package to raise more States income but protect low earners
Changes to make Guernsey's buses more reliable
Aurigny plane makes emergency landing after leaving Guernsey