Belarus has summoned the Ukrainian ambassador, saying it had changeable down a Ukrainian aerial defence rocket successful Belarusian territory.
It happened during 1 of Russia's heaviest aerial onslaughts against Ukraine truthful far.
Footage from Belarusian authorities tv appeared to amusement rocket debris successful a field.
A Ukrainian subject spokesperson said the incidental was "the effect of aerial defence".
Belarus - a cardinal state of Russia - demanded that Kyiv transportation retired a afloat investigation, aft the S-300 rocket came down adjacent the border.
The Ukrainian ambassador was called successful to the overseas ministry successful Minsk.
"The Belarusian broadside views this incidental arsenic highly serious," spokesperson Anatoly Glaz told the Reuters quality agency.
He called connected Ukraine to "take broad measures to forestall the recurrence of specified incidents successful the future".
Ukraine's defence ministry said it was acceptable to invitation experts from countries that bash not enactment "the violent authorities of Russia" to assistance analyse of the incident, adding that it reserved "the unconditional close to the defence and extortion of its ain sky".
It said it did not regularisation retired a "deliberate provocation" successful which Moscow launched its cruise missiles connected a way wherever they would beryllium intercepted implicit Belarusian territory.
Belarus said the rocket came down adjacent the colony of Harbacha successful the Brest region, astir 15 km (9 miles) from the borderline with Ukraine.
A witnesser told Radio Free Europe: "Our windows were shaking and the location was vibrating from what indispensable person been a dependable wave."
The subject commissar of the Brest region, Oleg Konovalov, sought to downplay the incident.
"Unfortunately, these things happen," helium said successful a video posted to societal media.
Belarus allowed Russia to usage its territory successful February to commencement the penetration of Ukraine.
Ukrainian officials precocious claimed that Russia could beryllium readying a caller violative from Belarus, but Western governments accidental they person seen nary grounds of that.
Meanwhile, Ukrainian President Volodymyr Zelensky said astir regions were without powerfulness successful freezing conditions pursuing a immense question of Russian rocket attacks.
Moscow fired scores of missiles astatine cities crossed Ukraine connected Thursday, including successful Kyiv, Kharkiv, Lviv and Odesa.
Mr Zelensky warned that Moscow "is lone driving itself deeper into a dormant end".
"The presumption of the largest violent successful the satellite volition person consequences for Russia and its citizens for a agelong time. And each rocket lone confirms that each this indispensable extremity with a tribunal. This is precisely what volition happen," helium said.