Ukrainian President Volodymyr Zelensky visited Bucha, a town northwest of Kyiv, after photographs of civilian bodies found strewn across a street sparked outrage.
Speaking to media, Zelensky said that Ukraine wants to "show the world" what happened in Bucha. He added that the country will "not pause" until it finds those accountable, CNN reported.
Donning a flak jacket and surrounded by security, the Ukrainian president stated it is "very important to us that the press is here" in the town.
"We want you to show the world what happened here. What the Russian military did. What the Russian Federation did in peaceful Ukraine. It was important for you to see that these were civilians," he added.
Meanwhile, the European Union on Monday announced it has established a joint investigation team with Ukraine to probe alleged Russian war crimes and crimes against humanity.
Also, UN Secretary-General Antonio Guterres urged on Sunday to conduct an independent probe of the killing of civilians in the Ukrainian town of Bucha.
"I am deeply shocked by the images of civilians killed in Bucha, Ukraine. It is essential that an independent investigation leads to effective accountability," Guterres tweeted.
On the other hand, Russian defense ministry has called this a staged operation by the Ukrainian authorities.