When Arash Hampay set out from his native Iran, he envisioned Europe as a safe haven from the torture and interrogations he had endured in his homeland.

Before leaving Tehran, Hampay, a 32-year-old activist and community organiser, had been imprisoned for several months for allegedly forming an illegal political group. He insists that he was targeted for his political activism and had no choice but to flee the country.

Yet, he found a different reality when he landed on Greek shores after taking a dinghy from Turkey across the Aegean Sea in September 2016.

"I have not experienced my human rights being respected here in Greece," he told Al Jazeera, citing poor living conditions in refugee camps and residences, police discrimination, being barred from employment and institutional deprivation.

Although Greek authorities eventually granted Hampay asylum, his brother, who travelled with him from Iran, was denied. While his appeal remains under consideration, Hampay's brother is not allowed to leave Lesbos.

In the meantime, Hampay is waiting with his brother on the island. "Here they deal with us as prisoners and hostages," he said.

His sentiments are common among refugees and migrants stuck on Greece's eastern Aegean Islands. And with aid groups observing a sharp surge in the number of arrivals, tensions are boiling over.

Nearly 200 refugees and migrants are reaching Greek shores each day, putting the arrival rate at the highest since March 2016, according to the UK-based charity Save the Children.

"Slow asylum processes mean people are stuck on the islands indefinitely, and families with children are having to live in makeshift shelters with water shortages, poor sanitation and insufficient toilets," Save the Children said in a recent press release. "Rats and insects have infested living areas, and improvised electrical wiring poses danger to children."

Since the beginning of August, the group estimates, more than 6,000 people have arrived.

Addressing the Greek parliament last week, Migration Minister Yiannis Mouzalas cited a "noticeable increase" in refugee arrivals.

The minister insisted that the uptick "is not at a level to create the sense that the deal between the European Union and Turkey for stricter inspections and hampering [refugee] flows is collapsing".

'Unacceptable'

Elinor Raikes, the International Rescue Committee's regional director for Europe and North Africa, points to the March 2015 European Union-Turkey agreement to stem the flow of refugees to Europe as one of the main reasons behind declining living conditions.

As part of that agreement, the Greek government is meant to send refugees who arrived after March 20, 2016, back to Turkey for asylum process. From Turkey, successful applicants should be relocated in Europe.

That agreement led to tens of thousands of refugees and migrants being bottlenecked in Greece.

Since the agreement was made, the Greek government has barred travel from the islands to the mainland for asylum seekers whose applications have yet to be accepted, although exceptions are made for emergencies.

"As a result of the so-called geographical restriction, some of the most vulnerable cases, including those suffering from PTSD, survivors of torture, and pregnant women, are being forced to wait in overcrowded, ill-equipped hot spots, in some cases even in tents, for months at a time, to have their asylum claims heard," Raikes told Al Jazeera.

"Not only is this unacceptable, it also adds to the backlog."

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She added: "Every effort must be made to allow vulnerable cases to travel immediately to the mainland to apply for asylum there. Political considerations cannot get in the way of people's safety and wellbeing."

The United Nations refugee agency, known as the UNHCR, says most refugee sites have become more efficient since the initial outbreak of the refugee crisis in 2015.

As of September 30, the UNHCR had recorded the arrival of 136,423 refugees and migrants to Europe via the Mediterranean Sea. Of that total, nearly 20,000 had made it to Greece, while the rest had travelled from Libya to Italy.

Since the start of 2017, at least 2,681 people have gone missing or died at sea, according to the UNHCR.

Overcrowding and self-harm

Although the number of arrivals pales in comparison the peak months in 2015, when around 10,000 refugees and migrants arrived each day, the surge has resulted in worsening living conditions on Greek islands.

"On the eastern Aegean Islands, and particularly in the hotspots, the situation has once again become alarming and the hosting capacity has been overwhelmed," said Boris Cheshirkov, UNHCR's Associate Communications Officer on the Greek islands.

Explaining that the "vast majority" of arrivals since the spring of 2017 are fleeing the ongoing bloodshed in Iraq and Syria, Cheshirkov explained that more than 4,800 people made the treacherous journey from Turkey in September.

On Samos Island, some 2,000 asylum seekers are crammed in a refugee centre designed to accommodate only 700 people.

On nearby Lesbos Island, more than 5,000 people are currently living in an area equipped for only 2,000, and the declining humanitarian conditions have had tragic consequences. "Pregnant women, people with disabilities and families are enduring the deteriorating conditions," Cheshirkov added.

"Tensions are rising and the risk of violence, including sexual violence, is increasing … Conditions and prolonged stay for some is affecting people's mental health," he continued, adding that reports of "incidents of self-harm" are routine.

READ MORE: Refugees in Greece - 'We are living in a prison here'

Overcrowding, a lack of resources and slow transfers of asylum seekers to mainland Greece have exacerbated the poor living conditions.

Critics and activists say the humanitarian situation has only grown worse since the government took over aid services in August after the European emergency funding for refugees ended.

"Progress made in reception facilities must be maintained and reinforced, but overall conditions need considerable improvement," Cheshirkov said.

Waiting for a Greek court to decide his brother's fate back in Lesbos, Hampay recalled a "humiliating" incident in which a police officer recently detained him and a fellow asylum seeker while he arbitrarily checked their documents.

"I see this as fascistic behaviour because it only targets refugees," he said.

"The island is relaxing and beautiful [for Greeks and tourists], but it is torture and prison for us refugees."

Follow Patrick Strickland on Twitter: @P_Strickland_