BEIRUT -- The last time Lebanese security forces randomly stopped him for interrogation at a checkpoint this year, 28-year-old Khaled demanded an explanation. He had lived here as a refugee fleeing the Syrian Civil War since 2011, and he had already been detained four times. They responded with a slap to his cheek and continued their humiliating questioning.

“Why did you leave your hometown in Daraa and come here?” one officer asked, recounted Khaled -- whose real name is being withheld for security reasons -- last week over dinner with three other Syrians who also fled the war and now live in Beirut’s Christian neighborhood of Ayn al Remmaneh.

One of four people in Lebanon today is a Syrian refugee. Syria is less than two hours away from Beirut, and since the war began there four years ago, almost 2 million people have come to Lebanon. Some are living in camps near the border, while many made it to Beirut and other cities, where even those who managed to find employment face brutal discrimination stemming from economic pressure and from Syria’s four-decade history of involvement, often heavy-handed, in Lebanon’s own civil war and ongoing sectarian conflicts.

Many Syrians are regarded as second-class people in Beirut, regardless of their citizenship of financial status. As such, they are frequently subjected to arbitrary interrogations by Lebanese security officials and nationality-based discrimination by average citizens.

Their sheer numbers are instilling in many Lebanese the fear that Syrians are taking over.

“Refugees? I don’t know about them,” said a waiter at Coop D’Etat, a rooftop bar in the bohemian neighborhood of Gemayzeh. But then he came back to the table and added, “By the way, Lebanese people are refugees in this country now.”

“Any Lebanese person can beat you up just for being Syrian,” said Safwan Khatib, a refugee from Homs who now runs the media office of an independent Syrian refugee human-rights group.

It wasn’t always this way. Syrians fleeing the war used to be more welcome, but then the war dragged on -- and the flow of refugees became a flood.

“Receptivity towards refugees in Lebanon was very strong at the outset of the crisis,” said a report by the United Nations High Commissioner For Refugees. "However, as the years have progressed, the numbers increased and the strain deepened, receptivity has waned.”

It has been 40 years since the Lebanese Civil War broke out in 1975 and almost a decade since the Syrian army, which invaded the country under the pretext of ending the war, finally left. The enmity many Lebanese feel toward Syria from that period is compounded by the Bashar Assad regime’s involvement in Lebanese politics, including its alleged role in the assassination of popular former Prime Minister Rafik Hariri in a devastating suicide bombing in Beirut.­­

Today, even people who help refugees for a living are wary.

“If I hear that there are Syrian refugees living in my area, I would be upset,” said Nadia Abou Naccoul, a psychologist who works with refugees in Arsal, a city on the border with Syria. “It’s our country. If Syrians came here, they would take over.”

Despite sharing a language, the Syrian accent is a dead giveaway, even before security forces ask to see an identification card, Khaled said. The rise of the Islamic State group in Syria, as well as of Islamist militias battling the Lebanese army and Shiite Hezbollah fighters on the border, has made Lebanese security forces especially anxious about infiltration by radicals.

“Why are you growing your beard so long?” Khaled said an officer asked him during his latest interrogation. “The last time we stopped you, it was short. Why do you keep changing your look?”

The implied accusation that he looked like a Sunni jihadist was obvious. Khaled said security forces had been keeping a file on him since the first time they arrested him more than a year ago. He supports the revolution, but claimed he was never a fighter in Syria.

“If you want to curse someone Syrian, you call them ‘Daesh,Homs refugee Khatib said, using an Arabic term for the Islamic State group.

New laws imposed by the Lebanese government require all Syrian refugees to pay $200 annual fees and produce rental contracts as well as notarized letters promising they will not work in the country, forcing many to do so illegally to make ends meet.

Some refugee families resort to forcing their children to beg. Ragged Syrian children in Beirut are frequently seen begging on the streets, where the police often round them up and arrest them.  

One of the children, 9-year-old Abdullah, works the streets of the tiny, cosmopolitan Hamra neighborhood with four other Syrian boys, two of them his cousins and all of them refugees from Damascus and Lattakia. Before the war, they would have been in school. Here, they spend their days trying to sell a pack of gum for 300 Lebanese pounds (20 cents) or shining shoes with the small wooden kits they carry. The boys claimed they used the money to buy food -- but when offered food instead of cash, all but one refused.

As Lebanese police circled the area, the boys’ eyes darted to the nearest alleyway. Ahmed, the most skeptical of the five, hesitated for a second before explaining that they had already been arrested once. Seeking to avoid being caught again, the boys scattered.

If the children arent apprehended by police, they will be met on a street corner at the end of the day by an adult, who will collect the lion’s share of their earnings. In most cases, the children -- and there are many of them among the Range Rovers on the streets of Hamra -- get to keep less than 5 percent.

Life isn’t much better for the Syrians at the opposite end of the socioeconomic spectrum, those who have managed to get out of the camps and hold jobs.

Omar, whose full name and place of employment cannot be disclosed for security reasons, said he likes his job. But the pay is low, “probably because I am Syrian,” he said.

Syrian refugees were permitted to work in certain industries at the outset of the war, but now the government’s restrictions are all but preventing them from legal work because “refugees are seen as taking jobs away from [the] Lebanese,” according to the U.N.’s refugee agency.

Later that evening, Omar admitted one reason he liked his job is because it lets him keep a low profile. There are no checkpoints on his way home from work, and he barely has to deal with Lebanese people and security forces.

“No one in the world likes refugees,” he said. “Here it is too small, and there are too many.”