Thousands of refugees and asylum seekers who have fled conflict zones such as Syria, Eritrea and Sudan are being left destitute in Britain, according to a report from the Red Cross. The figure has increased by 10% in the last year.

The charity, the largest provider of services to asylum seekers and refugees in the UK, with centres in more than 50 towns and cities, expressed concern about the increase in the numbers of vulnerable and destitute people who have fled war and conflict being helped by its staff and volunteers in 2016.

Almost 15,000 (14,909) people without adequate access to food, housing or healthcare last year received food parcels, clothing and small amounts of cash, an increase of nearly 10% on the 13,660 in 2015. In 2014 just 11,268 people were supported. The youngest recipient of support was a child of one, the oldest was 92.

There are many more destitute asylum seekers and refugees trying to survive across the UK than those supported by the Red Cross, but it is hard to get precise figures as many are living “underground” and do not appear in Home Office records.

A study carried out by the London School of Economics in 2009 estimated that in London alone there were more than 350,000 refused asylum seekers. Many cannot return home because their countries are too dangerous or they cannot obtain travel documents. These countries include Eritrea, Iran, Somalia and the Democratic Republic of Congo.

Mike Adamson, chief executive of the British Red Cross, said: “These figures point to a steady increase in the number of people who flee war and violence only to risk being left destitute and reliant on charities for basic necessities, including the ability to feed and clothe their children.”

At least 21% of those seen had refugee status, and thus a legal right to protection and to remain in the UK. Forty-six per cent were asylum seekers awaiting a decision on their initial application to remain in the UK, and who were entitled to housing and approximately £36 a week to cover basic living costs (known as Section 95 support).

The Red Cross is seeing people most frequently in Leicester, London and Cardiff.

“It’s clear that our asylum system can leave anyone destitute, from families with young children to older people, including individuals who the Home Office has deemed in need of international protection,” Adamson added.

“No one should be left homeless after fleeing the devastating conflict in Syria or persecution in Eritrea. Instead of creating a more hostile system which puts even more people at risk of living hand to mouth, we want to work with the government to address this largely hidden and silent crisis.”

Some asylum seekers are forced to sleep on night buses or on park benches and women in particular are vulnerable to sexual exploitation. Many are reliant on charities to feed them.

One female asylum seeker who fled Eritrea after suffering persecution there and was initially refused asylum by the Home Office became destitute and was forced to sleep at train stations. One night she was approached by a man she did not know who offered to let her sleep at his home because it was so cold outside. She agreed to go with him but when they arrived at his home he raped her. She became pregnant as a result of the rape. She was later granted refugee status by the Home Office.

“My life was too horrible when I was hungry and sleeping outside,” she said. “I was scared and hungry all the time. If I had been given Home Office support while I was an asylum seeker I am sure I would not have been raped. Now I have refugee status I am trying to move forward with my life with my baby.”

A Home Office spokesperson said: “Asylum seekers who would otherwise be destitute are supported by the Home Office. The UK has a proud history of granting asylum to those who need our protection, but those who are refused asylum and have exhausted their appeal rights are expected to leave the UK.”