Russia has repeatedly struck Ukraine using Iskander missiles according to Kyiv's military intelligence agency.
Authorities in Kyiv said early on Thursday that two children had been killed as a result of the strikes, although this has yet to be confirmed.
The Iskander tactical missile system crashed into a road safety barrier in St. Petersburg.
Russia has maintained significant forces in Belarus to threaten Ukraine's northern border, and in March said it would deploy nuclear weapons there.
An important supply route for military resources was reportedly struck overnight by an Iskander missile.
Russian missile squads practiced firing Iskander missiles in simulated radiation and chemical contamination environments, the Baltic Fleet said.
The former general called it an "undefendable policy" as the U.S. recently promised additional defense systems.
"Let's demilitarize the terrorist state to live in peace!" said Ukrainian Defense Minister Oleksii Reznikov.
Russia Releases Images Showing Off Its Iskander Missile System
The 9K720 Iskander is a mobile short-range ballistic missile system produced and deployed by the Russian military.
Two short-range ballistic missiles were launched on Wednesday in North Korea's second such test in less than a week.
New satellite images show Iskander ballistic missile units conducting drills within range of the border.
The U.S.-led NATO Western military alliance and Russia accused each other of fueling the Cold War–like crisis across Europe.
The new rocket is one of several developed for a short-range ballistic missile system that replaces nuclear-tipped arms, which are prohibited by an international treaty.
Poland has long called for U.S. backing in deterring Moscow, and Russian missiles are set to arrive near its border.
Russia's decision last year to deploy of the Iskander-M to a region bordering Poland and Lithuania prompted concern among both NATO allies.
Iskander units were drafted in the exercise close to the Estonian border.