
The United Nations refugee agency has called for 17,000 migrants who are trapped and living rough on the streets of the Greek island of Lesbos to be evacuated.

Migrants have been left on the streets of island's main port town after a delay in processing permits that will allow them to continue their journey into Europe.

It comes a day after yet more violent clashes erupted between overwhelmed police and thousands of asylum seekers today as young men fainted in the afternoon heat as officers threatened their batons at the frenzied crowds.

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Turmoil: Violence erupted between migrants and island police on Saturday in Lesbos as authorities continue to struggle with the swelling number of people arriving on the small island

Violence: A Greek police officer threatens crowds with his baton as he and others try to control crowds waiting to be registered at the port

Desperate: Thousands descended on the port on Saturday to have their details taken before being able to board ferries bound for Athens

Overwhelmed: A man is comforted by a friend as he shouts in pain after being caught in the chaos at Lesbos port on Saturday afternoon

Some collapsed after being stricken while frightened children wept in their mother's arms.

Many of the migrants are living in makeshift camps without proper beds, sanitation and running water.

Now Alessandra Morelli, a representative of the UN High Comminssioner for Refugees has said the migrants should be evacuated from the Greek island.

She told the Telegraph: 'We are calling today for an evacuation of the refugees on Lesbos, in order to relieve the pressure.'

While a UNHCR official added: 'The situation is becoming unmanageable. The longer the refugees stay, the harder it becomes for the islanders to tolerate the situation.'

The new plans to evacuate the refugees to the port of Piraeus, near Athens, would see them be allowed to board ferries, depsite not having travel documents.

They would then be registered when arriving on the Greek mainland.

Life or death: A man has his pulse checked as he lies on the ground after becoming overwhelmed by the crowds in Lesbos port

Fight: A young migrant lies on a cardboard sheet as he has his body examined after being stricken in the clashes with police on Saturday

Futile: A man bleeds from the mouth after being stricken in the chaos on Saturday afternoon. The island's mayor has pleaded with Athens to send more resources to help cope with the worsening crisis

Fragile: A woman is held up by a friend as she appears to faint in the sweltering afternoon heat in Lesbos as thousands rush to be registered by authorities

Chaos: Thousands are waiting in the port to board ferries bound for Athens but have been unable to secure tickets. The Greek government has laid on only two charted services

Patient: Scores of migrants wait in the port in the hope of winning a coveted space on one of the few ferries taking people to mainland Greece

At the moment without permits, the migrants are unable to buy ferry tickets or book hotels in Lesbos.

Thousands have flocked to Greece in the hope of journeying on to mainland Europe after making the treacherous crossing from their war-stricken homes.

Scores less fortunate have already died on rickety boats launched by people smugglers. Among them a newborn baby boy, plucked from the water on Saturday off the nearby island of Agathonisi.

Earlier the island's mayor appealed for 'immediate measures' to help relieve strain on its resources.

Sypros Galinos likened the scenario to a bomb in his hands, pleading: 'I appeal to the prime minister for immediate measures. We will have victims.'

Lesbos is the entry point for around half of the hundreds of thousands of those who have fled to Greece this year. There are thought to be around 17,000 refugees on the island, around half of whom are already registered and awaiting transport to Athens.

Inundated: The island has been overwhelmed by the vast number of asylum seekers arriving every day, leaving local authorities struggling to cope

Distraught: A frightened child cries into his mother's chest as she is comforted by a family member. They are queuing to be registered in the hope of then gaining access to a ferry to Athens

Hope: Members of one family cradle their children as they wait at the port on Saturday. Around 15,000 are thought to have flocked to Lesbos

Between Thursday and Friday morning the Greek coastguard said it had rescued some 500 people from the water.

In Kos, another crucial port for thousands seeking asylum, hostile protesters have taken to the streets. One group brandished bats and shouted 'go back to your countries' as some arrived on the island on Thursday night, sparking criticism from Amnesty International that the police did not intervene quickly enough.

It is urging Greek and European authorities to drastically improve the conditions migrants face on arrival. There are thought to be around 4,000 migrants in Kos.

In central Europe the first signs of relief were seen on Saturday as scores arrived in Austria and Germany after abandoning hopes of settling in Hungary.

Hundreds marched on the M1 motorway between Budapest and Vienna after their comrades were tricked into boarding trains bound for designated migrant camps. They feared they would face reprisals from far-right Hungarian authorities if they agreed to be registered in the country, instead fleeing for Austria.

Angela Merkel invited thousands of refugees to settle in Germany, telling world leaders that none would be turned away once they reached the Austrian border.

Around 10,000 are expected to arrive across German cities today from Hungary and Austria. Meanwhile David Cameron has pledged that Britain will take in 'thousands' more migrants and increased the country's foreign aid commitment.