The shooting allegedly started Sunday after a member of the group, which this year broke away from the "Oficia de Envigado" crime syndicate of drug traffickers, threw a grenade at a police patrol, the news website Colombia Reports said Monday.
Those killed in the ensuing gun battle included three police officers, one gang member and a civilian shot while in his home, the website said the newspaper El Colombiano reported.
The arrested gang leader, Naranjo Juan Camilo Martinez, is known as "Gomelo," the website said the newspaper El Tiempo reported.
He was "gravely injured" in the gun battle, Colombia Reports said.
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