Ukrainian officials have invited the media to a site in the city of Bucha, near Kyiv, where Russian troops are said to have tortured and killed civilians.

Journalists from NHK and other media organizations on Monday were shown a storage space in the basement of a camp site.

Ukrainian officials say the bodies of three young men were found in a room closest to the entrance.

Bullet marks could be seen on the concrete walls.

A Ukrainian soldier who served as a guide said Russian troops are believed to have tortured citizens to obtain information on the whereabouts of Ukrainian soldiers and police officers.

A report by the Organization for Security and Co-operation in Europe says Russian forces waterboarded prisoners in "torture chambers" at the camp site.

It says the bodies of men dressed in civilian clothes and covered in burns were discovered there.

Local officials say at least 426 bodies have been found in Bucha since Russian forces withdrew from the city in late March.

The deputy mayor said the city wants the international community to learn about all the citizens who were killed, identify those responsible and bring them to justice.