Police in Rio de Janeiro arrested 16 people, including 11 military police, accused of selling confiscated firearms to criminal groups.

According to news site R7, the group operated a gun trafficking ring that sold weapons to gangs based in Rio’s third-largest favela, Jacarezinho.

This is one of Rio’s poorer areas, where crack cocaine use is widespread, and prison gang the Red Command (Comando Vermelho) is active.

Jacarezinho does not yet have a police pacification unit, known as UPPs. The UPPs have been presented as highly-trained community police forces, whose employees are well paid and unlikely to take bribes or collaborate with criminals. In September, however, one UPP commander was fired for accepting bribes in exchange for allowing drug and weapons to be sold in certain areas.

As Jacarezinho remains one of Rio’s most crime-ridden favelas, it would make sense that demand for weapons remains particularly high here. There are some concerns that Rio’s more powerful gangs may have found refuge in Jazarezinho after being driven from other larger favelas, including Rochinha and Complexo de Alemao.

Since initiating the UPP program in 2008, the government has led highly publicized security raids in these areas, aiming to clear the favelas of gangs then re-establish social control.