Child refugees are being abused, detained and illegally sent back to Italy by French border guards, according to a new report from Oxfam.

Some children as young as 12 were being held overnight in cells without food, water or blankets, or access to an official guardian, the report states.

These conditions are contrary to French and European Union (EU) law.

French police routinely stop unaccompanied children and put them on trains back to Italy after altering their paperwork, either to make them appear older or to make it look as though they want to be sent back, the report states.

Border guards have also cut the soles of the children’s shoes or stolen their mobile phone’s SIM cards, Oxfam staff said.

One Eritrean girl, described as “very young”, was forced to walk along a road with no pavement while carrying her 40-day-old baby.

An estimated 16,500 refugees and migrants passed through the Italian border town of Ventimiglia in the nine months to April.

The majority were fleeing war and persecution in countries such as Syria, Afghanistan, Sudan and Eritrea. Many were trying to reach other countries in the EU, such as the UK, France, Germany and Sweden.

French police routinely stop unaccompanied children and put them on trains back to Italy after altering their paperwork, report alleges (Oxfam)

Around a quarter are thought to be children, who have reported feeling abandoned in reception centres.

They said they were given no opportunity to attend schools or training, while being provided with no information about how to claim asylum or reunite with family members in other European countries.

After months or even years of waiting, many decide to continue their journey alone, while others are pushed out of the centres as soon as they turn 18.

Many sleep under a motorway just outside the town of Ventimiglia, as the only nearby reception facility has a heavy police presence and compulsory fingerprinting which may deter them from staying there.

Refugee crisis - in pictures Show all 27 1 /27 Refugee crisis - in pictures Refugee crisis - in pictures A child looks through the fence at the Moria detention camp for migrants and refugees at the island of Lesbos on May 24, 2016. AFP/Getty Images Refugee crisis - in pictures Ahmad Zarour, 32, from Syria, reacts after his rescue by MOAS (Migrant Offshore Aid Station) while attempting to reach the Greek island of Agathonisi, Dodecanese, southeastern Agean Sea Refugee crisis - in pictures Syrian migrants holding life vests gather onto a pebble beach in the Yesil liman district of Canakkale, northwestern Turkey, after being stopped by Turkish police in their attempt to reach the Greek island of Lesbos on 29 January 2016. 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Refugee crisis - in pictures A refugee holds two children as dozens arrive on an overcrowded boat on the Greek island of Lesbos Refugee crisis - in pictures A child, covered by emergency blankets, reacts as she arrives, with other refugees and migrants, on the Greek island of Lesbos, At least five migrants including three children, died after four boats sank between Turkey and Greece, as rescue workers searched the sea for dozens more, the Greek coastguard said Refugee crisis - in pictures Migrants wait under outside the Moria registration camp on the Lesbos. 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Macedonia is a key transit country in the Balkans migration route into the EU, with thousands of asylum seekers - many of them from Syria, Afghanistan, Iraq and Somalia - entering the country every day Getty Images Refugee crisis - in pictures An aerial picture shows the "New Jungle" refugee camp where some 3,500 people live while they attempt to enter Britain, near the port of Calais, northern France Getty Images Refugee crisis - in pictures A Syrian girl reacts as she helped by a volunteer upon her arrival from Turkey on the Greek island of Lesbos, after having crossed the Aegean Sea EPA Refugee crisis - in pictures Refugees arrive by boat on the Greek island of Lesbos after crossing the Aegean sea from Turkey Getty Images Refugee crisis - in pictures Beds ready for use for migrants and refugees are prepared at a processing center on January 27, 2016 in Passau, Germany. 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While sleeping rough, they have no access to clean water or toilets, and their tents or cardboard shacks are often destroyed on the orders of the local authorities.

“Children, women and men fleeing persecution and war should not suffer further abuse and neglect at the hands of the authorities in France and Italy,” Elisa Bacciotti, campaigns director at Oxfam Italy, said.

“In too many cases, a lack of basic services and information in Italy’s reception system is forcing people into precarious and dangerous situations. People with a simple desire to claim asylum in a country where their family members live are being thwarted at every turn.”

She added: “Europe must fix its asylum system, and share the responsibility for hosting asylum seekers. Governments and border officials should protect the special needs and rights of children instead of illegally pushing them back to other countries. Children should never be kept in jail cells or subjected to cruel abuse.”

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The Oxfam report, titled Nowhere but Out, calls on EU member states to ensure responsibility for refugees is shared more equally.

It also calls on the EU to take into account the legitimate needs of asylum seekers and to ensure families are reunited.

It demands the French government immediately stops illegally returning children to Italy and works to put an end to the alleged abuse conducted by French police and border guards.