Greece is expressing concerns that a recent wave of North African immigrants may seek to enter their border via Turkey.
Istanbul becomes a hub to human smugglers
Istanbul, Turkey's largest city, is only a few hours drive to the Greek border. Its international airport offers direct flights to most African and Middle Eastern countries and there are few visa requirements for most people entering.
This combination has made the city one of the centers for people seeking to enter the European Union illegally whether for political or economic reasons.
Many turn to what is known as a "connection man" who links the migrants with human smugglers who assist them across the border.
It is a 'big business,' says smuggler
One of these of "connection men" is Michael - not his real name. He is from West Africa, and says human smuggling in Istanbul is now a big business, but it is not without risks.
"So it's easy. It's a big business. There is a lot of money involved," he said. "That's why there are new people now involved in this way. To my knowledge I have almost 10 or 12 contacts. The main route to Greece: They can go by land or by ship," continued Michael. "But by ship - usually one voyage per 3 months. By land there is a voyage one time a week. But there are more risks by land . If your food finishes or you get bad [sick], maybe you can die, they will forget you there. No one will take care or you. And the second risk is that as Turkey and Greece were once long time enemies, there are mine lands in the border. There are people dying in this way."
EU: 80,000 illegal migrants per year into Greece
Despite the risk, the EU says 80,000 illegal migrants enter Greece through Turkey every year . One of them is David from Nigeria.
"One time I tried to the best I can, to cross over to Greece. All they promised us we are bringing you a boat. All we saw was a balloon boat," he said. "And, because of the distance, we travelled for two days. I saved the life of two guys who were with me. Both were so afraid that they could not even handle anything. But I alone I was able to paddle the balloon boat and we went across to Greece. But by the time we got across the police caught us and kept us in cells for one week, two weeks, three weeks."
David was eventually deported back to Turkey, where he is now considering another attempt.
To stem the growing flow of migrants, EU border police were sent to help Greek security forces. Athens now fears with the Middle East and Northern Africa turmoil those numbers could rise even further.
Leaders discuss illegal immigration
The Greek minister responsible for illegal migration, Christos Papoutsis, visited Ankara earlier this month to discuss the issue.
Professor Ahmet Icduygu of Istanbul's Koc University warns that human smuggling is becoming increasingly sophisticated
"Overall, I say its a very well working system, through the networks of the friends and relatives," said Icduygu. "And the mobile phones, it's quite important in all this smuggling and trafficking business."
Competition in human smuggling business
According to experts, human smuggling has become a multimillion dollar business. Connection man, Michael says such competition is driving prices down and now many migrants only have to pay if the trip to their destination is successful.
"No one pays cash [upfront] now because of the competition," said Michael. "If I have a friend who wants to go Italy, I present myself as a guarantor and take his money. And, when he reaches Athens or Rome he calls me, meaning that he is safe, he is now in Europe. And, then I call the guy and pay him."
The increasingly level of sophistication of human smugglers along with the growing competition can only make Istanbul even more attractive to would-be migrants. Observers say with the escalating turmoil in Libya and other countries in the region in the coming months could well see business growing for the human smugglers.