They are collecting evidence for investigations into alleged war crimes.
ADVERTISEMENTWith a backdrop of bombed-out apartment buildings and rubble in Borodianka, in Kyiv's suburbs, rescue personnel work 24 hours a day to clean up what's left of this city.
But, in addition to the clear-up, they are also collecting evidence for investigations into alleged war crimes.
In Borodianka alone, more than 1,300 explosives have been found, according to Yurii Cehniuk, head of the special operations unit at Ukraine's state emergency service.
"During the bombing of the city aviation bombs were used 250 and 500 kg ones, the forbidden cluster bombs that covered the area (and those we destroyed at the scene) and Grad rocket launching systems shelled the surrounding settlements," said Cehniuk.
"Of course, it's a war crime. These are civilian's houses where civilians lived and at the time of the shelling no armed forces units were here. No armed forces were here, they shelled a peaceful city, including the forbidden cluster bombs that were dropped directly on this square, on the city centre."
Non-governmental organisations such as Truth Hounds are also working in the field. They don't want to be identified for security reasons. But they explain how they work.
"We questioned people, whose acquittances were taken prisoners, so-called "prisoners", who suffered torture and abuse. Also, we have testimonies about the executions of civilians," said a member of Truth Hounds.
Evidence is collected, catalogued and sent to national and international authorities.