SAO PAULO - Police in Brazil say four homeless men are dead and four others hospitalized in critical condition after drinking from a bottle containing a “suspicious liquid” given to them by unidentified people in the city of Sao Paulo.

Police are investigating the case as a possible mass poisoning in the neighbourhood known as “Cracolandia,” or “Crackland,” which is infamous for open drug use.

A police statement says a survivor told authorities the men were offered a bottle they believed contained alcohol Saturday. After drinking it they became sick and four of the men later died in the hospital. The four survivors are in serious condition.

Police are testing the contents of the bottle, which they described as a “suspicious liquid,” and are searching for the people who provided the bottle.