Authorities in Russian Federation say observers from Sweden, Poland, Lithuania, Estonia, Latvia and Norway have attended the war games, while Vladimir Putin visited the site on Monday.
Earlier, the news site 66.ru reported that two spectators had been hospitalized with serious injuries.
It said Tuesday two people were wounded and two vehicles destroyed in the incident during the Zapad (West) 2017 maneuvers.
The Zapad 2017 joint exercises of the Russian and Belarusian armed forces are being held from 14-20 September. According to the sources, three people were lightly injured and two cars damaged, and the military is already carrying out an investigation.
Emmys: What time does the show start, who will win, who hosts?
The 69th Primetime Emmy Award ceremony will be aired live at 8 pm ET/ 5 pm ET (September 17) on CBS . This tough category of talent will also have Carrie Coon from Fargo and American Crime's Felicity.
The military exercises are taking place from September 14-20 in western Russian Federation and include 13,000 military personnel from Russian Federation and Belarus.
A ministry of defense press release last Sunday, the night before Putin arrived, said that Zapad exercises with Ka-52 helicopters had successfully carried out rocket strikes on ground targets at the Luzhsky range.
Russia's defence ministry said no-one was injured in the incident.
Life.ru also published footage, which it says shows the same incident from the ground and which differs from the original video published online.
Senate Republicans seek elusive 50th vote in latest effort to repeal Obamacare
Republicans in the Senate are considering voting on another Obamacare repeal bill before September 30, Politico reported . McCain spokeswoman Julie Tarallo said the senator is continuing to "review" the text Cassidy introduced last week .
The Russian Defense Ministry's news service denied that the incident took place on Monday, which is the day when Russian President Vladimir Putin visited the region.
"The targeting system of one of the helicopters locked onto the wrong target". One of the helicopters fired several rockets that appeared to hit a vehicle close to the spectators.
"All the reports on social media about a barrage of rockets hitting a crowd of journalist and a large number of casualties are either a deliberate provocation or someone's personal stupidity".
Trump Administration Reconsiders Climate Change Policy
Washington's exit of the Paris agreement could cause others to exit, which would undermine a deal that took years to negotiate. Trump drew worldwide criticism when he declared the US would pull out of the Paris Agreement and seek a renegotiation.