Apart from those three Nobel Prize winners, the campaign whose aim is also to support women in Syria and female refugees has involved a dozen non-governmental organisations, too.
Croatia's Interior Minister Ranko Ostojic briefed the three guests of the state of affairs in the Slavonski Brod camp.
Addressing the press, Williams said that terrorism such was seen in Paris last Friday must not incite fear, xenophobia and intolerance towards Muslims.
The three Noble Peace prize winners expressed concern over increasingly frequent announcements of sealing the borders to deter refugees.
To close the border is not a solution, this is another crime against people who are searching better life. They are fleeing their terrorism-affected countries, Karman said.
Ebadi called for abiding by the convention on refugees' rights, and recalled that 7% of refugees passing through Croatia were her compatriots who left their motherland owing to unbearable living conditions.
After four and a half years of war, 12.5 million Syrians are dislocated, 240,000 have been killed and all are fleeing to save their lives, said Donna McKay of the Physician for Human Rights organisation.
This delegation visited the Serbian border town of Sid on Tuesday morning and they are set to visit the Dobova refugee centre in Slovenia on Wednesday.