A boat leaving Turkey on July 7 loaded with up to 40 refugees capsized between the Greek islands of Agathonisi and Farmakonisi.
Authorities say 19 people were rescued: eight by the Greek Coast Guard, 11 by the Turkish Coast Guard. Five bodies were retrieved and up to 16 people are still missing and feared to have drowned.
"Greece's volatile economic situation, combined with the increasing numbers of new arrivals, is putting severe strain on small island communities, which lack the basic infrastructure and services to adequately respond to the growing humanitarian needs," UNHCR spokesperson William Spindler told a press briefing in Geneva.
UNHCR said that the number of people arriving is now so high that, despite all efforts, the authorities and local communities can no longer cope.
A majority of the refugees arriving in Greece are moving onward, trying to reach countries in western and northern Europe through the western Balkans region. Countries in this region such as the Former Yugoslav Republic of Macedonia (fYROM) and Serbia, have witnessed a dramatic increase in the number of refugees. In the first half of this year, some 45,000 people sought asylum in the region. This represents almost a ninefold increase of asylum applications compared with the same period in 2014.
However, these are only some of the refugees entering the two countries, with most continuing directly on their way to Hungary and further north. It is estimated that half of all refugees who are actually passing through the region do so without being registered by the authorities, and are exposed to violence and abuse by smugglers and criminal gangs.
"An urgent response from Europe is needed before the situation deteriorates further," Spindler added.
He said that in the course of June, the number of people crossing every day from Greece into Macedonia and Serbia surged from 200 to 1,000. Over 90 per cent of those traveling this route are from refugee-producing countries, mainly Syria, Afghanistan, Iraq, Eritrea and Somalia.
As with Greece, the capacity of these countries to effectively respond to the emergency situation is severely overstretched. While the authorities are trying to alleviate the situation by establishing facilities to receive and process them, UNHCR is concerned about reports of border police preventing refugees from entering.
In some instances, refugees have alleged that some police officers are using violence and pushing them back into the hands of smugglers.
"The tightening of borders is not the solution, including the plans of the Hungarian government to build a fence along the Serbian border. Reports of push-backs at the borders between Serbia and Macedonia and between Macedonia and Greece are worrying, as such practices place refugees at further risk and are contrary to states' legal obligations," Spindler said.
On the northern Aegean island of Lesvos, the number of new arrivals far outstrips the capacity of the police-run identification centre in Moria. More than 3,000 refugees are currently living in difficult conditions at the makeshift accommodation site of Cara Tepe, and 1,000 are camping outside the Moria facility.
"UNHCR has previously expressed concern for the well-being of refugees, including pregnant women and children, who are having to walk up to 60 kilometres through the mountains to reach the island's main town of Mytiline," Spindler emphasized.
UNHCR stressed however that despite the precarious situation facing the livelihoods of many Greek people, their response towards refugees has for the most part been welcoming and generous.