Caracas, Venezuela (CNN) -- Dramatic video posted to YouTube purports to show the initial moments of an attack against Venezuelan opposition presidential candidate Maria Corina Machado and her supporters.
The video begins with the candidate addressing residents and reporters shortly after she threw the first pitch in a softball game. Thirty seconds into the roughly 50-second clip, several gunshots ring out; people scatter. Some board a bus while a voice in the video shouts: "Go, go, go!"
CNN could not confirm the authenticity of the video, allegedly taken on Saturday in a neighborhood on the east side of the capital, Caracas.
Separately, El Nacional newspaper published a photo of what it said was the shooting, showing two people on a motorcycle. Wearing a red T-shirt, the man on the back is pointing a gun at a bus.
It was not clear from the video whether Machado boarded the bus, nor whether the bus in the video was the same as the one in the photograph. However, a campaign spokesman told CNN en Español a pair of people on a motorcycle fired shots into a bus carrying Machado and her supporters.
Machado, who was not injured in the incident, also said that shots were fired in the open, and at her vehicle.
Machado is one of several presidential candidates who will participate in a primary election next year. The winner will be the unity opposition candidate to run against President Hugo Chavez.
She spoke to CNN en Español shortly after the attack, which Machado said left one person injured.
She blamed "criminal gangs" for the shooting and faulted the national government for ceding control.
"The government has absolutely lost control and, in many cases, has been complicit with the criminal gangs," she said. Machado accused the government of providing some groups with weapons.
CNN contacted the Interior and Justice Ministry and the Venezuelan Ministry of Communication and Information for comment on the incident, but did not receive a response.
Journalist Osmary Hernandez contributed to this report.