The graves of the children are easy to discern, little bumps on the ground squeezed in along the edges of the cemetery. A rectangle of four small concrete blocks is enough to encompass one child’s entire body.

No names are carved in marble, just overgrown, withered grass rustling in the breeze of the Bekaa Valley. In the cemetery named al-Rahma, meaning Mercy, only one Syrian refugee child’s tombstone bears markings – an illegible name etched into the stone with a rough tool, the mark of a despairing parent.

“You see these little graves that we put on the side? They’re all children, and they’re almost all Syrians,” said Hosni Shuqayyif, the cemetery caretaker. “There are so many children. We bury them in the corners, on the sides, or between the other graves, wherever there is space.”

The number of Syrians who have fled their country after six years of war passed 5 million on Thursday. More than a million of those are registered with the UN high commissioner for refugees in Lebanon, compared with a prewar Lebanese population of 4 million, the per capita equivalent of the UK hosting 13 million refugees.

But in this tiny nation, with its 18 official religious sects, Syrians have endured many indignities – from onerous visa procedures to poor treatment and humiliation at the border and residency offices, to child labour, sexual exploitation, and life in fragile plastic tents that collapse in winter, and the xenophobia of local politicians pandering to fearful followers.

And now, death brings a final indignity. Families of dead Syrians living in Lebanon are increasingly struggling to find a place to bury their loved ones, often leaving them for weeks or months in hospital morgues while they search for cemeteries that will take them. They struggle to scrape together enough money to pay off hospital fees, sometimes carrying them in cardboard boxes or in the backs of taxis and digging graves with their bare hands.

A tiny grave at al-Rahma cemetery. Photograph: Kareem Shaheen/The Guardian

NGOs sometimes negotiate deals with municipalities to allow refugees to share cemeteries with the Lebanese, but they are growing overcrowded because of the large population of Syrians, often outnumbering locals by three or four times. Few landowners are willing to sell land to build graveyards, worried about plunging real estate prices and superstitions, and religious authorities are staying clear of the problem.

Most Syrians, who are banned from work, cannot even afford the $200-$300 cost of burial, including performing Islamic rites of cleansing, or shrouds and gravestones, and donors are few.

“They’re not finally at ease when they are dead,” said Haytham Taimey, a Lebanese sheikh who runs the Development and Renewal Association, an NGO that helps Syrians find and pay for burial spots. “Even human emotions, when you’ve lost somebody close to you, their basic right of mourning and saying goodbye, Syrians don’t have that any more.”

There is no comprehensive data for mortality rates among Syrian refugees in Lebanon. UNHCR only finds out about deaths if a family opts to tell them, an unlikely step since it could mean a reduction in aid, or if a person who is receiving medical support dies in hospital. The organisation counted 2,087 deaths in 2015, though the number is likely much higher given the Syrian population and the limits on reporting.

A spokesperson for UNHCR said they were aware of problems finding burial spots, and while the organisation cannot assist with burial procedures, it provides counselling to families and tries to put them in touch with NGOs that can help.

“UNHCR is aware of the general difficulties that Syrian refugees face in burying their loved ones in Lebanon,” the spokesperson said. “When UNHCR is alerted to specific issues, we ask our local partners to help refugees resolve this through dialogue. Local and religious authorities, local partners and municipalities are among the parties that could help refugees solve these issues.”

In the past, Arab cemeteries often included a section labeled “madafen al-ghoraba”, or the “graveyards of the strangers”, for visitors who passed away – a now defunct practice.

Walid Luwais, an official at the Islamic endowments authority, acknowledged that the issue amounted to a crisis, but said that even when the government buys land for a cemetery plot neighbours often refuse to allow the burial.

“People don’t want graves near them, it’s a popular superstition,” said Taimey, the local sheikh. “They love life and they don’t want to open their windows and be reminded of the afterlife. They have to be hidden from view, though to be honest dead people are better neighbours, they never do anything to harm you.”

Some municipalities have come up with solutions, allowing Syrians who live in refugee camps in their towns to bury their dead in a designated area of the cemetery, while turning away outsiders. One such town is Omariyah, which houses 15,000 Syrian refugees to 7,000 Lebanese, and where half of the local cemetery is occupied by dead Syrians.

Grave at Omariyah cemetary. Photograph: Kareem Shaheen/The Guardian

“It is a real crisis,” said Mohammad al-Ahmad, the town’s mayor, who helped institute the rule. He said it was still painful to turn away desperate Syrians. “Imagine someone coming to you who can’t find a place to bury his dead loved one. When he asks you: ‘So where do I go with my dead relative? In Syria I’m homeless, and here I can’t even bury my relative.’ You don’t know what to do. Of course he should have a burial place,” he said.

For Syrians in Lebanon, that heartbreak is a daily occurrence, and the calls to Taimey and local youth organisations are too frequent. One man, who declined to give his name, had to carry his father in the back of a pickup truck for hours until he managed to find a burial spot in a cemetery late at night, burying him without a coffin.

Fighting back tears, he walked away saying: “They want us to just throw our dead in the street.”

There is no shortage of stories of the desperate plight of Syrians. One volunteer with a youth group in Saadnayel, a town that hosts about 26,000 Syrians, described how they had to bury a 50-year-old man who had been in a morgue for 40 days. Hospitals will often keep custody of corpses if the victim has no paperwork or if his family owes money.

“There was a man who arrived in a taxi, and he had his son with him in a cardboard box,” said Shuqayyif, the cemetery caretaker. “A cardboard box. Not even a wooden casket. A cardboard box that probably had had potatoes or shoes in it. I saw that myself. And the father is there, digging with his hands to bury his child. It’s heartbreaking.”