Four people were arrested Thursday on charges of smuggling drugs and weapons to neighboring Uruguay, Brazilian authorities said.
The group worked in the southern state of Rio Grande do Sul and "were in partnership with Uruguayan traffickers," police said.
The criminal network used intercity buses to smuggle arms and drugs, mainly crack and marijuana. They sold cannabis for one-third of the price in Uruguayan pharmacies, where pot can be purchased legally.
Authorities arrested four members of the gang on Thursday, while two Uruguayans had been detained at an earlier point in the investigation.
One of the suspects arrested on Thursday was the reputed leader of the Brazilian end of the operation.
Investigators found that the drugs were smuggled from Brazil to Montevideo and other cities in Uruguay, such as Rio Branco, Melo and Treinta y Tres.
Police seized drugs, ammunition, documents and cell-phones from the suspects.