Masked gunmen have killed at least 19 people and injured seven more in a series of shootings on the outskirts of Brazil’s largest city of Sao Paulo, authorities say.

« This is very serious and merits a special investigation, » said Secretary of Public Security for Sao Paulo State Alexandre de Moraes in a Friday statement. « We don’t rule out any possibility. »

According to de Moraes, the shootings were the « largest killing of the year » that occurred Thursday night local time. He further added that a total of 15 individuals were killed in the city of Osasco, three in Barueri and one in Itapevi, all of which lie within Sao Paulo’s metropolitan area  (…)