2016 Rio Games: Brazil Reviews Olympic Torch Security After Riot

Rio's top security official has vowed to review security for the Olympic torch after rioting protesters blocked the relay ceremony and apparently extinguished the flame.

The violent clashes late Wednesday in Angra dos Reis, a coastal resort south of Rio, cast a shadow over final preparations for South America's first Olympics, which start August 5.

In another worry for organisers, Rio metro employees threatened yesterday to go on strike on the eve of the Games if they do not get a 9.83 per cent salary raise, raising the possibility of transport chaos for some 500,000 tourists expected to attend.

Rio de Janeiro state security secretary Jose Mariano Beltrame said that policing during the torch relay -- which will have visited more than 300 Brazilian cities by the time of the opening ceremony in Rio's Maracana stadium -- needs improving.

"There has never been a problem," he was quoted as saying by G1 news site. "Yesterday there was one. This needs to be reevaluated and we will be paying more attention to this question."

"Extinguishing the torch is a crime," he warned.

Tear gas

The crowd, protesting a lack of public transport and the late payment of salaries by the nearly bankrupt Rio state, attacked the procession in Angra dos Reis before being driven off by police using tear gas and rubber bullets.

In footage of the clashes shared online and on Globo television, someone can be heard shouting triumphantly: "The torch has been put out!" as the torch bearer, carrying an unlit torch, is hustled into the safety of a bus.

The Rio organising committee said in a statement that the torch relay "had to be temporarily interrupted".