It is very hard to stand here face to face with the horrors one man can do to another, Meron told reporters at the grave which probably contains the remains of hundreds more victims of the mass crimes committed by Bosnian Serb paramilitaries.
Meron said Tomasica reminded him of the crimes committed in the Holocaust, in which members of his family had been killed too.
Tomasica is one the biggest mass graves discovered in Bosnia after 1995 and is believed to contain the remains of a majority of about 1,000 people from the Prijedor area who are still unaccounted for.
In their ethnic cleansing campaign, Serb forces killed more than 3,000 Croats and Bosniaks in that area in 1992.
The Tomasica mass grave was discovered this year thanks to information proved by two former Bosnian Serb soldiers.
I honestly hope the work of the tribunal in The Hague and the national courts in the region will bring the perpetrators of the crimes to justice and provide at least partial consolation to the survivors and victims' families, said Meron, who was on a three-day working visit to Bosnia.
On Tuesday, he is scheduled to visit the former Omarska detention camp for non-Serbs near Prijedor, after which he will go to Sarajevo to attend a conference on the 20th anniversary of the ICTY.