The boy 'hero', 11, who fled Ukraine alone with a backpack, his passport and a phone number written on his hand

An 11-year-old boy who fled Ukraine alone with only a backpack, his passport and a phone number scrawled in ink on his hand has been hailed as a 'hero'.

The youngster managed to reach the Slovakian border on his own - and was promptly called a 'hero of the night' by the authorities after crossing to safety.

The boy, wearing a bobble hat, had just a backpack, a plastic bag, his passport and the telephone number written on the back of his palm, according to the Slovak Ministry of Interior. The report has not been independently verified.

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"He came all alone because his parents had to stay in Ukraine. Volunteers took care of him, took him to a warm place and gave him food and drink,” the ministry said, reports The Mirror.

The boy hasn't been named. Images showed him being given a hot drink and support by border officials.

The statement, posted on the ministry’s Facebook page on Sunday, said that thanks to the information written on the boy's hand and on a piece of paper that was folded in his passport, staff at the border were able to get in touch with the boy's relatives in Slovakia, who were then able to come and collect him.

"He won over everyone with his smile, fearlessness and determination worthy of a real hero," the statement said.

It is not clear why the boy was unaccompanied, with his parents reportedly remaining in Kyiv, which is continuing to suffer extensive Russian shelling. The UN estimates that 1.5m people have left Ukraine since the outbreak of war on February 24 - that amounts to about 3.5% of the total population.

The majority of them have fled to Poland but other counties such as Hungary,