Greece has appealed to its European Union partners to come up with a comprehensive strategy to deal with a growing migrant crisis as new data showed 21,000 refugees landed on Greek shores last week alone.

That number is almost half Greece's overall refugee intake in 2014 and brings total arrivals this year to 160,000, even as it struggles with a debt crisis that has forced it to accept a third international bailout.

The influx of refugees, mainly from Syria, has strained an already ill-prepared reception system in Greece that relies heavily on volunteers, forcing thousands to camp out in filthy conditions and triggering sporadic clashes and brawls.

A spokesman for the United Nations refugee agency UNHCR in Geneva said Greece needed to show 'much more leadership' in dealing with the crisis.

But Greek officials said they needed better coordination within the European Union. "This problem cannot be solved by imposing stringent legal processes in Greece, and, certainly, not by overturning the boats," said government spokeswoman Olga Gerovassili.

Nor could it be addressed by building fences, she said.

Earlier this month construction began on a 175 km (110 mile) razor wire border fence in Hungary to deter migrants, while Britain and France have tightened security on the French side of the 30 km (18.6 miles) sea tunnel separating the countries at Calais.

Greece, which is in the throes of its worst economic crisis in generations, criticised other European countries for being more of a hindrance than a help as bottlenecks were reported not only in getting into the country, but getting out on its northern land borders.

"This country doesn't have the financial resources or the infrastructure to get through this in a dignified manner," Gerovassili said.

In addition to overcrowded conditions on some of its Aegean islands, problems were compounded by a lack of transport to take refugees to the Greek mainland at the peak of the summer vacation season.

"There are about 4,000 people waiting for transfer on Lesbos right now and arrivals are continuing," said Katerina Selacha, a volunteer with Aggalia, a non-governmental organisation on the Greek island. "Conditions are pretty difficult."

UNHCR officials said only three Greek islands had organised reception facilities for refugees but that they were inadequate.

There were chaotic scenes on the island of Kos last week, where local police locked migrants in an outdoors athletics stadium to process them. On one occasion police used fire extinguishers to keep crowds back. 

Germany may receive 750,000 migrants this year

Germany expects up to 750,000 people to seek asylum this year, a business daily cited government sources as saying,up from a previous estimate of 450,000, as some cities say they already cannot cope and hostility towards migrants surges in some areas.

The influx has driven the issue of asylum seekers high up Germany's political agenda. Chancellor Angela Merkel has tried to address fears among some voters that migrants will eat up taxpayers' money and take their jobs. The number of attacks on refugee shelters has soared this year.

The interior ministry declined to comment on the figures reported in the Handelsblatt but is set to issue its latest predictions this week. Its previous estimate for asylum applications in 2015 was already double those recorded in 2014.

Germany is the biggest recipient of asylum seekers in the European Union, which has been overwhelmed by refugees fleeing war and poverty in countries such as Syria, Iraq and Eritrea.

There is also a flood of asylum seekers from Balkan countries. Almost half of the refugees who went to Germany in the first half of the year came from southeast Europe.

Along with a shortage of refugee lodgings in cities including Berlin, Munich and Hamburg, Germany also struggles to process applications, which can take over a year. Merkel has long said this must be accelerated.

The finance ministry has seconded 50 customs officials to the National Office for Migration and Refugees for six months to get through the backlog.

After Germany, Sweden is the next most generous recipient of asylum seekers in Europe. In 2014, it recorded 81,200 application and anti-immigration sentiment is on the rise.

The U.N. High Commissioner for refugees Antonio Guterres told Die Welt daily that Germany and Sweden were bearing too much of the burden.

"In the long run it is not sustainable that only two EU countries -- Germany and Sweden -- with effective asylum structures accept the majority of refugees," he said.

Both Merkel and President Joachim Gauck have urged Germans to shun intolerance and hostility towards foreigners.

In the first six months of the year, Germany saw 150 arson or other attacks that damaged or destroyed refugee shelters, nearly as many as in the whole of last year. Many have taken place in former Communist eastern states.

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