(Reuters) -An assistant to Ukraine's military commander-in-chief was killed in an explosion on Monday in what Interior Minister Ihor Klymenko described as an accident.
Klymenko, writing on the Telegram messaging app, said the assistant to Commander-in-Chief General Valery Zaluzhnyi had returned home with birthday gifts from colleagues, including a box of Western-manufactured grenades that he was showing to his son.
"The son first took the munition in his hand and began to twist the ring," Klymenko wrote of the incident that killed Major Hennady Chastyakov. "Then, the serviceman took the grenade from the child and pulled the ring, causing a tragic explosion."
Klymenko said the colleague who presented the gift had been identified and two more grenades of this type were found in his office as an investigation got under way. He said he had issued the explanation so as not to "spread unofficial information."
Zaluzhnyi had earlier expressed condolences to Chastyakov's family, saying "an unknown explosive device went off in one of his presents".
The Ukrainska Pravda online news outlet said Chastyakov's 13-year-old son suffered serious injuries. A security source told Ukrainska Pravda that Chastyakov, 39, was a graduate of a military academy and fully trained in handling grenades.
Zaluzhnyi has had a high profile in the more than 20-month-old Russian invasion. Last week, he wrote an essay in the Economist magazine saying the war had entered a new phase of attrition that was to Russia's advantage and calling for more sophisticated technology for Ukraine's military.
President Volodymyr Zelenskiy had denied any suggestion that the war has entered into a stalemate.
(Reporting by Ron Popeski in WinnipegEditing by Bill Berkrot and Matthew Lewis)