Some of the Syrians fleeing the conflict in their country have crossed Turkey aiming for Greece, in order to claim asylum in the European Union. But to get there they have to take to boats - and there have been persistent reports of Greek officials pushing them back into Turkish waters, sometimes with fatal results.

"Everything we would do for our families and our fathers, we do the same thing for these people. We bury them in the Islamic way," says Ekrem Serif-Oamadoglou, as he points to 400 freshly dug graves clustered on the remote hillside.

The cemetery is just outside Sidiro, a Muslim village on the Greek side of the Evros river, close to where it forms a fast-flowing, kilometre-wide barrier between Greece and Turkey.

The 400 dead are all people who have drowned as they attempted to cross the river and slip illegally into Europe. It is only here, at the end, that they find friends in Greece, the members of the local Muslim community who bury them.

"They came from places all over the world, but we regard them as brothers," says Serif-Oamadoglou, the local imam's son. "They came here for a better life, but unfortunately they were unlucky."

They told me that their boats had been capsized and pushed back by a Greek boat - they say it was the Greek coastguard Adib Hachach, Syrian in Athens

A large portion of those currently seeking that better life are Syrians fleeing the violence that has riven their homeland.

For two years now TV news crews have filmed lines of mainly women and children making their undignified exit along the dusty roads that lead from Syria into Turkey.

On foot, carrying plastic bags filled with clothes and household items grabbed at the last minute, they are now crossing at the rate of 7,000 a day, according to the UN.

Some stop in the refugee camps which dot the borderlands or try their luck in towns like Gaziantep, 100 km (62 miles) into Turkey and now home to 57,000 Syrians. But those with money move on to Istanbul, the ancient crossroads between East and West and gateway to Europe.

From there migrants until recently travelled to Edirne, a city which sits right on the Evros river. Under cover of darkness, smugglers put them into rubber boats and pushed them off into the dangerous currents.

Salwa al-Rajo's family made the journey six months ago as part of a group of 40 Syrians.

They fled Syria because the father worked in government intelligence and the rebels were threatening to kill them - but it is the crossing over the Evros that still gives them nightmares.

While they tried to cross the river, they drowned - the currents are so strong, as you know Maj Gen Emmanouil Katriadakis, Government immigration spokesman

Mrs al-Rajo says that, to her horror, when their boat got to the Greek side, the police there separated them and pushed them back.

"We were put into a rubber boat. I didn't know where my children were, or my husband. I was about to fall into the water, I grabbed the policeman's hand, but he knocked me away," she says.

"There was another woman who lost her glasses. She said, 'I can't get in to the boat, I can't see.' The policeman started to beat her up. Her son said, 'Why are you beating my mum? She's an old woman.' The policeman got his gun and put it to his head and said, 'Shut up!' And so they got us in to the boat and pushed us in to the water."

There have been many reports of refugees being pushed back into the river, but Greek police reject the claim.

"There were some cases that, while they tried to cross the river, they drowned. The currents are so strong, as you know," says Major General Emmanouil Katriadakis, the government spokesman on immigration.

"But nothing like this has happened since Operation Shield took effect because now we are present on the river banks and if people are in danger we go to help them."

Find out more Watch Sue Lloyd-Roberts' film on Our World: Fleeing Syria at these times [BST] on the BBC News Channel: Sat June 8 at 0530 & 2130 and Sun June 9 at 0330, 1430 & 2130. And on BBC World News at these times [GMT]: Fri June 7 at 2330, Sat June 8 at 1130 & 1630 and Sun June 8 at 1730 & 2230 Her Newsnight film can be seen on the BBC iPlayer and Newsnight website.

Operation Shield was launched last summer to close what was Europe's most porous border. All EU police forces now take their turn in helping the Greeks patrol the frontline.

Now if the river alone fails to stop migrants there are patrol boats full of sophisticated detection equipment, foot patrols and sniffer dogs on the shore, and a formidable fence which was completed a few months ago at a cost of 20m euros (£17m).

So the Syrian refugees must now choose another route.

Starting from Istanbul again, the refugees are taken by road to Turkey's western Mediterranean coast from where it is just 12km (7.5 miles) to the closest of the Greek islands, Lesbos, with the border between the two countries running along the water in between.

If you have money and a European passport it is a pleasant and comfortable ride across the Aegean. If not it is a journey filled with danger.

Deysem Siti, head of the Kurdish community in the nearby Turkish city of Izmir, was present as the bodies of 66 drowned Kurdish Syrians were dragged ashore in September 2012.

"These people don't care. They put the women and kids below the deck and locked it. It was a small boat, built for 20 people, they put 110 people in it," he recalls.

"It couldn't carry the weight. It only got 10m from the shore when it sank."

"Thirty-three of them were children, I saw a two-month-old, five-year-old, three-year-old, seven years, there were young women in their 20s. I saw a child, the only survivor of a family of 11 - his father, mother, sisters and brothers were all dead."

The incident is just one of many. Hundreds of refugees are known to have drowned over the last year, but the true total is uncertain because not all bodies are found.

Just a few weeks ago, Adib Hachach, a Syrian who has lived in Athens for 12 years, received a call from the coastguard at Lesbos, to collect the bodies and belongings of his brother Omar, his sister-in-law and their three young children, all of whom had drowned.

Media playback is unsupported on your device Media caption Syrian Adib Hachach on the deaths of his brother's family

The remains of the youngest, two-year-old Fatima, have never been found.

Hachach says that he spoke to survivors from other smuggling boats which had set out at the same time.

More from the Magazine Syria's civil war has forced more than a million people to flee, usually with only a small bag of possessions. Brian Sokol, with support from the UNHCR, has photographed some of the refugees holding treasures from their homes. In pictures: Syria refugee keepsakes (March 2013)

"They told me that their boats had been capsized and pushed back by a Greek boat. They say it was the Greek coastguard. There were nine on my brother's boat and none survived, so I will never know the truth," he says, sobbing.

Refugee support organisations have been getting many reports of a deliberate "push back policy" by the Greek police and coastguard in which survivors claim boats are shoved from Greek waters back into Turkish ones, a dangerous tactic at sea and at night when most of the smugglers' boats operate.

Amnesty International has collected information on 40 alleged incidents from the Aegean sea and the Evros in recent months.

The Greek police and coastguard robustly deny the claims. On a night patrol with the Greek coastguard, the boat's skipper Lyropoulos Vasilis tells me, "This is a big lie".

The refugees put themselves at risk, he says, by deliberately scuppering their vessels when they see a patrol boat, so that the coastguard will be forced to rescue them and carry them to Lesbos.

Those that make it to the island are met by volunteer doctors who check the new arrivals over, but neither food nor shelter is offered by the authorities.

When I visit the quayside where they end up, I see a group of about 40 people, including women and children, left out in the open to spend an uncomfortable night in the rain just metres from the bright lights of Mytilene, one of Greece's most popular holiday resorts.

Their only meal is provided by a soup kitchen which was set up by volunteers on the island to help locals hit by the Greek economic crisis, but which is now pressed into helping those in even greater need.

I abandoned my hijab and I and my daughter wear make-up, so we look European, because we are afraid that the racists will hurt us Salwa al-Rajo, refugee

After 36 hours on the island the refugees are allowed to take a ferry to the mainland, but there they face many further hazards.

More than 9,000 Syrians have been arrested and detained in the country over the last two years, and only two out of the hundreds of Syrians who have applied for asylum have been given it - an approval rate of less than 1%, compared with the 90% rate for Syrians applying elsewhere in Europe.

The al-Rajo family ended up in a prison in Greece for several months, after their second attempt to cross the Evros.

The family of six has now been released, but is stranded in a one-bedroom apartment in Athens paid for by members of the Syrian community.

Salwa al-Rajo says that they sold everything they owned in Syria to fund their escape, but have lost all of their money to the river smugglers and another trafficker whom they say swindled them out of 18,000 euros (£15,000) paid in a bid to secure fake passports and passage to Sweden.

The older boys in the al-Rajo family do not dare leave their apartment for fear of arrest.

Al-Rajo and her 17-year-old daughter, Walaa Ulwan, have taken to disguising themselves. Both of them have uncovered heads, the mother's hair is dyed blonde, the daughter's is blonde with pink streaks. They each have garishly painted nails and wear make-up.

"When I first came, I wore the hijab, but people told us that the fascists would attack us because we looked like Arabs and would kill us," al-Rajo explains. "So I abandoned my hijab, I changed my hair colour and I and my daughter now wear make-up, so we look European. We did all this because we are afraid that the racists will hurt us."

Greece's right-wing, anti-immigration party, Golden Dawn, now holds third place in popular support among political parties in Greece.

Beset by a harsh austerity programme, the Greeks have little time for the thousands of Syrians at their door. The truth is that the Greeks do not want the Syrians and the Syrians do not want to stay in Greece. But, having made it to here, they are stuck.

Media playback is unsupported on your device Media caption Watch Sue Lloyd-Roberts' full Newsnight report as she follows the journey made by Syrian refugees trying to make their way into Europe

You can watch Our World: Fleeing Syria at these times [BST] on the BBC News Channel: Sat June 8 at 0530 & 2130 and Sun June 9 at 0330, 1430 & 2130

And on BBC World News at these times [GMT]: Fri June 7 at 2330, Sat June 8 at 1130 & 1630 and Sun June 8 at 1730 & 2230

You can follow the Magazine on Twitter and on Facebook