Brazilian police detained another man suspected of having links to terrorism, a week before the Olympic Games get underway in Rio de Janeiro, local media reported Thursday.

The 28-year-old arrested had published several texts on social networks showing sympathy for extremist Islamic groups, the man's lawyer told local media on Thursday.

The Brazilian man, with Lebanese grandparents, had been arrested back in 2014 for illegally carrying a firearm.

The lawyer assured there is no definite accusation against his client and the arrest was only part of preliminary investigations based on the texts his client published on social networks.

The arrest came one week after Brazil's police detained 12 people who were allegedly planning an attack at the Olympic Games and the alleged group carried out a virtual baptism in order to form part of the militant group of the ISIS.

Brazil's government announced that security had been increased ahead of the Games.

The security plan will include 85,000 troops from the military, police and National Security Force. There will also be a restriction in place on the air space during the Games.