(CNN) -- At least four people were killed when a tourist trolley derailed Saturday in Rio de Janeiro, Brazil, state media reported. About 30 people were injured in the accident, the state-run Agencia Brasil reported, citing firefighters. The trolley went off the tracks in Rio de Janeiro's hilltop Santa Teresa neighborhood, Agencia Brasil said. CNN affiliate TV Record showed images of rescuers carrying injured passengers away from the wreckage on stretchers. Investigators are trying to determine what caused the accident, TV Record reported. A French tourist died two months ago after falling out of one of the trolleys, Agencia Brasil said. Rio de Janeiro is scheduled to host the World Cup in 2014 and the Summer Olympics in 2016.
About 30 people are injured, state-run Agencia Brasil reports . Investigators are trying to determine what caused the accident, TV Record says . The accident occurs in a hilltop neighborhood .