Luiz Alberto Sallaberry is counterterrorism director for Brazil's National Intelligence Agency.
The state-run news agency Agencia Brasil quotes him as saying that attacks in other countries and the growing number of Brazilians sympathizing with the Islamic State group has increased the possibility a terrorist attack.
Sallaberry was speaking during a public security conference this week about possible threats during the Olympic Games in Rio de Janeiro.
He says a threatening tweet posted late last year by a French convert to Islam was credible. In the tweet, Maxime Hauchard said Brazil was the Islamic State's next target.