Ten people were shot, three fatally, by gunmen.
A senior investigator told reporters that a number of suspects were arrested during operations in communities in Montego Bay.
Five illegal weapons, including an Uzi submachine gun, were seized.
The ten victims were shot when men in a car opened fire on occupants in another vehicle on Cottage Road, McCathy Street and Hart Street on October 6.
Several passers-by, including a ten-year-old, were shot in the attack.
The little girl, who was shot in the head, remains hospitalised in serious condition.