Five people were killed and 15 wounded when a group of gunmen opened fire on crowds of shoppers in Kingston. Authorities have put more than 100 police and soldiers onto the streets to prevent reprisals.
Police said there was no clear motive for the shooting spree, which happened late on Saturday, when the gunmen first shot shoppers in the Beckford Street area of downtown Kingston.
The gunmen then went to nearby Matthews Lane and Hannah Town, where they again shot into crowds.
Police said three people died on the streets and 17 were rushed to a hospital, where two others later died. None of the victims have been publicly identified.
Kingston Public Hospital officials said three of the 15 wounded were in critical condition.
The Caribbean nation of 2.7 million people has one of the world's highest murder rates and much of the violence is attributed to inner-city gangs linked to drug- and gun-trafficking.
Police also said they were working on a case in Clarendon, in central Jamaica, where three bodies were found in a shallow grave. Authorities suspect the men were shot to death and their bodies were dumped in the grave about a week ago.