Rio's police go on strike a week ahead of Carnival February 10, 2012 -- Updated 1434 GMT (2234 HKT) Police and firefighters protest in the historic center of Rio de Janeiro on Thursday. The strikes have raised concerns about escalating crime ahead of Carnival The country is gearing up for the 2014 World Cup and 2016 Olympics City of Salvador hit by wave of violence after police strike last week Sao Paulo, Brazil (CNN) -- Rio de Janeiro's police and firefighters declared a strike Friday, just a week before Carnival kicks off, raising fears of violence and crime as tourists arrive for the famed parades and street parties. Firefighters and the civil and military police announced the strike in a joint protest in downtown Rio, saying they would keep a third of their forces on the job, according to the state-run Agencia Brasil. But hours later, the commanding officers of the military police published a short statement saying all of their units were functioning normally. "There isn't any stoppage of any service for citizens," it said. It wasn't clear whether that meant members of military police rank and file were striking. Salvador -- Brazil's third largest city and a popular destination for Carnival -- was hit by a wave of killings and looting when its police launched a strike last week. The military helped quell the violence there, and more than 14,000 troops were on standby to move into Rio if necessary, according to Agencia Brasil. Police and firefighters are demanding wage increases. Rio attracts hundreds of thousands of tourists to its lavish Carnival celebration every year, and this year has an even higher profile because the country is gearing up for the soccer World Cup in 2014. The police strikes have heightened concerns over the country's ability to provide adequate security. Both Rio and Salvador are going to host games, and Rio is going to host the Olympic Games two years later.