A Brazilian policeman and his former colleague were arrested Thursday for alleged involvement in the execution-style killing of eight people at a fan club for football team Corinthians.

Armed men stormed the Sao Paulo fan club ahead of a semi-final match on April 18, reportedly ordering victims to lie together on the ground and then shooting them.

Authorities arrested Walter Pereira da Silva, an officer in Brazil's military police, and Rodney Dias dos Santos, a former officer in the same force who is now a suspected drug trafficker, a police spokesman said. Santos is suspected of ordering the massacre.

Investigators say the killings were likely a settling of scores related to drug trafficking.

Santos, 42, is accused of personally taking part in the killings.

The victims had gathered at the headquarters of the Pavilion 9 fan club to prepare for Corinthians' match against Sao Paulo rival Palmeiras.