Gunmen shot and killed 11 people, including five children, early on Saturday in a village in Guyana, a small South American country where gang violence is on the rise.
President Bharrat Jagdeo said the leaders of the massacre in the village of Lusignan, 11 miles east of the capital Georgetown, were linked to gunmen who attacked police headquarters in Georgetown on Friday night.
"These are animals and we have to hunt them down," Jagdeo said in a news conference broadcast on state television.
The government sent police and troops to the area to capture the gunmen and restore public order after angry residents protested the killings by blocking roads.
Jagdeo said the gang members were seeking to "spread terror" on Guyana's eastern coast and the killings were an attempt to inflame ethnic tensions between African and Indian Guyanese.
"The nature of this incident, carried out by unknown and reckless gunmen, (could) seriously affect the stability (of) race relations in Guyana," Robert Corbin, leader of Guyana's opposition parties, said in a statement.
Guyana has suffered from ethnic tension between populations of African and Indian descent and has struggled to contain rampant violence by roving gangs often linked to drug trafficking.
Gang members fired indiscriminately at police headquarters on Friday night, though no injuries were reported.
Officials say gang leader Rondell Rawlins has threatened to attack police installations after accusing them of kidnapping his girlfriend.
But the government has made no official statement linking Rawlins to the Lusignan killings.
Gunmen and troops on Wednesday exchanged gunfire in Buxton, also near Georgetown. One soldier was killed and another was wounded.
Police and the army urged people to avoid roads in the area of Lusignan while they restored order.