Video report by ITV News Correspondent Sangeeta Kandola
Hassan Alkhalaf, 11, has completed his 700-mile journey from Zaporizhzhia to Bratislava alone to be reunited with his siblings.
The boy's mother sent him with just his passport, two small bags and the phone number of a relative written on his hand as he left Ukraine on a packed train.
Thanks to the help of Slovak authorities and volunteers, Hasan's journey was a successful one.
“He was scared he had to get the train alone as the train was very full - there were 300 people in one carriage," Hassan's sister Luna explained.
Hassan's mother, Yulia, stayed in Ukraine to look after her immobile mother.
"I want to express my sincere gratitude to all the Slovak custom officers and volunteers who cared for my son," Julia said. "I am grateful that you saved my child’s life."