THE HAGUE, MAY 31

Representatives of a group of nations working together to investigate war crimes in Russia's invasion of Ukraine are meeting in The Hague amid ongoing calls for those responsible for atrocities to be brought to justice.

Tuesday's coordination meeting at the European Union's judicial cooperation agency, Eurojust, of members of a Joint Investigation Team and International Criminal Court Prosecutor Karim Khan comes as Russian forces continue to pound Ukrainian towns.

Moscow's invasion of Ukraine has been widely condemned as an illegal act of aggression. Russian forces have been accused of killing civilians in the Kyiv suburb of Bucha and of repeated attacks on civilian infrastructure including hospitals and a theater in the besieged city of Mariupol that was being used as a shelter by hundreds of civilians. An investigation by The Associated Press found evidence that the March 16 bombing killed close to 600 people inside and outside the building.

Since Russia invaded Ukraine on Feb. 24, the AP and PBS series Frontline have verified 273 potential war crimes.

Ukrainian President Volodymyr Zelenskyy has denounced killings of civilians as 'genocide' and 'war crimes,' while U.S. President Joe Biden has called Russian President Vladimir Putin 'a war criminal' who should be brought to trial.

The joint investigation team, made up of Ukraine, Lithuania and Poland, that is meeting Tuesday in The Hague was established in late March, a few weeks after the ICC opened an investigation in Ukraine, after dozens of the court's member states threw their weight behind an inquiry. Khan has visited Ukraine, including Bucha, and has a team of investigators in the country gathering evidence.

Ukraine's prosecutor general, Iryna Venediktova, will be among those at the meeting. Her office has already opened more than 8,000 criminal investigations related to the war and identified over 500 suspects, including Russian ministers, military commanders and propagandists. Last week, in the first case of its kind linked to the war, a Ukrainian court sentenced a captured Russian soldier to the maximum penalty of life in prison for killing a civilian.

Russia staunchly denies its troops are responsible for atrocities. The Defense Ministry said earlier this month that 'not a single civilian has faced any violent action by the Russian military.'

Analysts warn that the process of meting out justice will be long and complex as investigators piece together forensic and other evidence and seek to establish who ordered or knew about atrocities and failed to act to prevent or punish them.

The meeting in The Hague isn't the only place accountability is being sought.

Prosecutors in Poland, Germany, Lithuania, Latvia, Estonia, France, Slovakia, Sweden, Norway and Switzerland have opened investigations of their own. And there have been growing calls to set up a special tribunal to try Russia for the crime of aggression in Ukraine. The ICC can't prosecute the crime of aggression because neither Russia nor Ukraine are members of the court.