"We have fulfilled our mission," General Walter Souza Braga Netto, who led the Rio state security forces under a presidential decree since mid-February, said on Thursday.

Outgoing President Michel Temer took the drastic step of placing Rio security in the hands of the military, citing the police force's inability to control heavily armed drug gangs.

Army patrols had already been used in the impoverished favelas but the military intervention saw generals replace civilian authorities in top security jobs, as well as an increase in the use of soldiers to back up police.

The intervention was unheard of since the country's return to democracy in 1985 after 21 years of military rule.

It ends as planned on December 31, but the next governor of the state, Wilson Witzel, who takes office the following day, has already indicated that he intends to take a hard line against drug traffickers, including targeting them with the help of snipers.

His position is in line with far-right president-elect Jair Bolsonaro, a former soldier who sees guns as the answer to crime in a country with tens of thousands of homicides a year.

Residents of Rocinha, a Rio favela which is Brazil's most populous, hesitated in talking about results of the military intervention.

"This intervention is more political than effective, so I think nothing has changed," said Jose Luiz, a fashion designer, who sees "repressive politics" continuing.

- 'Better not to talk' -

"If I share my opinion about it, it will bring me serious problems. It's better not to talk," said Maria Goretti, a housewife.

From March to November, with the military at the helm of Rio security, the number of intentional homicides dropped by six percent compared to the same period the previous year, with significant decreases in the last four months, official figures show.

The data from Rio's Public Security Institute (ISP) also report a significant drop in the number of armed robberies of cargo-carrying vehicles, which were down almost 20 percent but still reached 6,675, compared to 8,301 during the same period in 2017.

The number of people killed in police operations, however, has increased by about 38 percent, meaning that the total number of violent deaths remains close to two percent higher than 2017, at 4,871 victims.

According to the ISP, 1,444 people have been killed by police since the beginning of the year, with December figures not yet available -- a record since this statistic began being compiled in 1999.

Additionally, 94 police officers were killed in 2018, compared to 134 the previous year.

From January 1, Witzel will manage security himself without the oversight of the military, but he has already pledged to use tough measures.

These include the training of snipers to kill armed criminals even if they don't pose an imminent threat to police, as well as the use of drones from Israel that could fire on traffickers from a distance.