Josipovic, Milanovic and Sprem were at the helm of a delegation of some 20 people, including deputy parliament speakers and members of Croatia's Anti-Fascist Alliance, and bowed before the monument marking possibly the biggest mass grave of Croats killed during death marches at the end of WWII.

"We came here to bow before the victims of death marches, notably all those who were not guilty and lost their lives without a trial," Josipovic briefly told the press.

Milanovic recalled that Tezno was the biggest mass grave where several thousand people were executed and buried.

"This is a war crime because they were executed without a trial and even if there had been a trial, a majority of those killed were young, innocent people who were members of another army, which is why, in our opinion, this is a place that needs to be visited," Milanovic said.

The PM said that the state leadership was interested only in the victims in Tezno, adding that the arrival in this town most definitely would not close up painful stories from the past because "there are those who live off conflicts and will always search for them."

Parliament Speaker Sprem said that for decades the truth about the victims of death marches had been withheld, adding that it was time to reconsider the law on national holidays and non-working days and that a memorial day should be marked in a different, more appropriate way.

"We will organise a comprehensive expert public debate in which the public will be included too and we will try to have memorial days marked in a more appropriate, contemporary European way," Sprem said.

Asked if the arrival of the top three Croatian state officials in Tezno could bother someone in Croatia, President Josipovic said he did not see how anyone could have a problem with commemorating this place in a dignified manner.

"We also decided to rationalise expenses. We have visited a lot of places in the past separately and now we will visit them together," the president said, adding that the state leadership was unified regardless of which party each person belonged to.

Wreaths were also laid by Slovenian Prime Minister Janez Jansa, who is scheduled to hold talks with his Croatian counterpart Milanovic.

Josipovic and Sprem returned to Croatia.

The mass grave at Tezno near the Slovenian city of Maribor is one of the biggest post-WWII mass graves in Slovenia, containing the remains of people killed by the Yugoslav communist authorities in 1945. It is probably the biggest mass grave of Croats killed during death marches on their way back from Bleiburg, Austria. The grave is an anti-tank trench several kilometres long, which contains the remains of at least 18,000 people, mostly Croatian civilians and soldiers of the Nazi-style Independent State of Croatia (NDH), who in late May 1945 were brought from a camp in Maribor to what today is the Dobrova cemetery and were executed there.