Ukraine's armed forces said Russian troops used stun grenades and gunfire to disperse a rally of pro-Ukrainian protesters in the occupied southern city of Kherson on Monday.
Russia did not immediately comment on the incident and Moscow denies targeting civilians.
Video obtained by Reuters shows protesters in Kherson's Freedom Square running to escape as projectiles land around them.
Loud bangs can be heard as smoke slowly fills the square. Gunfire can also be heard.
"Russian security forces ran up, started throwing stun grenades into the crowd and shooting," the Ukrainian armed forces' press service said in a statement.
It said at least one person was wounded but that it was unclear how they received their injuries.
Reuters was unable to independently verify what weapons were fired.
The city of Kherson, a regional capital of about 250,000 people, was the first big urban centre to fall into the hands of Russian troops after they invaded Ukraine on 24 February.
Russian servicemen hand out humanitarian aid to local people in Kherson, the first big urban centre to fall into the hands of Russian troops after they invaded Ukraine on 24 February. Credit: TASS/Sipa USA / AAP Photos
Earlier this month, the Ukrainian authorities said members of Russia's National Guard had detained more than 400 people in Kherson region for protesting against the occupation.
It accused Russia of trying to create a police state there.
Russia calls the war a "special military operation" to disarm Ukraine and protect it from "Nazis."
The West describes this as a false pretext for an unprovoked war of aggression to subdue a country President Vladimir Putin describes as illegitimate.
Ukraine demands meeting with Moscow
The news comes as Ukrainian President Volodymyr Zelenskyy said that it would not be possible to negotiate an end to the war in his country without meeting Kremlin leader Vladimir Putin.
Mr Zelenskyy told European public television networks on Monday such a meeting could discuss the future of occupied Ukrainian territory, but more time would be required to resolve the issue.
He also repeated his acknowledgement made earlier this month that Ukraine could not now secure NATO membership.
"I believe that until such time as we have a meeting with the president of the Russian Federation ... you cannot truly understand what they are prepared to do in order to stop the war and what they are prepared to do if we are not ready for this or that compromise," Mr Zelenskyy said.
Mr Zelenskyy has sought a meeting with Mr Putin for nearly a year, but the Russian leader has refused and instead demanded the Ukrainian president resolve his country's "civil war" with separatist territories linked to Moscow.
Since Russian troops poured into Ukraine last month, Mr Zelenskyy has issued increasingly urgent calls for talks to end the fighting.
Last week he called for a meeting quickly so that Russia could "limit the losses caused by its mistakes".
'Compromise must be found'
Russia's assault on Ukraine has killed thousands and driven almost a quarter of Ukraine's 44 million people from their homes.
Germany predicted the refugee number could reach as high as 10 million in coming weeks.
"I am ready at a meeting with the president of Russia to raise the issue of occupied territories, but I am certain that a solution will not come at this meeting," Mr Zelenskyy said in the interview.
He said several conditions would need to be met before such matters could be dealt with, namely, a cease-fire, the withdrawal of troops and security guarantees.
"If people are trying to stop a war, there is a cease-fire and troops are withdrawn. The presidents meet, reach an agreement on withdrawing troops and there are security guarantees of one sort or another," he said. "Compromises must be found, one way or another of guaranteeing our security."
Mr Zelenskyy said Ukraine is well aware it cannot be admitted into NATO now.
NATO member states, Mr Zelenskyy said, "understand that they do not want to fight with Russia and therefore cannot take us in ... we have to reconcile ourselves to that and say 'ok, other guarantees'".
