KYIV — At least 484 children have been killed and 992 injured since the start of Russia’s full-scale invasion of Ukraine, the Prosecutor General’s Office said Thursday as Ukraine marked International Children's Day.

“The Office of the Prosecutor General provides procedural guidance in proceedings on more than 2,900 war-related crimes against children: murder and injury, sexual violence, attacks on institutions and facilities for children, deportation, forced displacement, abduction,” it said in a statement.

Ukraine and most other eastern European post-Communist countries mark June 1 as International Children's Day. Towns, schools and community groups often organize children-focused events like sports days and fun fairs.

Ukraine’s first lady Olena Zelenska tweeted Thursday: "Children's Day has to be about safe childhood, summer, life... But today it is about new crimes of [Russian Federation] against Ukrainian children. A 9-year-old girl was killed in the shelling of Kyiv, and another is now in hospital.”

More than 2,500 educational institutions were damaged, including 256 completely destroyed, the Prosecutor General’s Office also said in its Thursday statement.

It added that more than 19,500 Ukrainian children have been forcibly deported to Russia or temporarily occupied territories. “But these are only the cases that are officially registered,” it said, warning the number could be higher.

War crimes: In March, the International Criminal Court (ICC) issued an arrest warrant for President Vladimir Putin and Russian official Maria Lvova-Belova for an alleged scheme to deport Ukrainian children to Russia.

The ICC charges, which relate to an alleged practice that CNN and others have reported on, were the first to be formally lodged against officials in Moscow since it began its unprovoked attack on Ukraine last year.

ICC President Judge Piotr Hofmanski told CNN in March that all signatory countries are "obliged to execute arrest warrants issued by the court," meaning that "there are 123 states -- two thirds of the states in the world -- in which he (Putin) will not be saved."

The Kremlin labeled the ICC’s actions as “outrageous and unacceptable” and said Russia does not recognize the jurisdiction of the court. — CNN