Sept. 19 (UPI) — The Russian defense ministry denied a media report Tuesday saying that spectators at a military exercise were injured by a helicopter’s rocket firing.

Conflicting reports indicate that two or three people were seriously injured Saturday when a Ka-52 attack helicopter fired air-to-surface rockets at a vehicle during the week-long “Zapad 2017” war games on the western borders of Russia and Belarus.

The Russian military called the incident “a purposeful provocation or someone’s personal stupidity,” adding that “No incidents involving army aviation happened in playing an episode pf practical actions” during the exercises. While it acknowledged that a single rocket was fired accidentally, it added that the rocket struck an empty truck and that no one was injured.

Media reports, notably that of the independent news website 66.ru, said once two cars caught fire, an explosion caused significant flying debris and the hospitalization of two people. The state-owned NTV television station reported no serious injuries but mentioned the damaged cars.

The Moscow Times reported the incident occurred Saturday or Sunday at the Luzhsky military range, near St. Petersburg, and that Russian president Vladimir Putin visited the range Monday.

A source identified by 66.ru said the victims were likely journalists.

About 12,500 Russian and Belarusian troops are involved in the war games, although some NATO countries near the action have placed the figure higher.