AGADEZ, Niger >> Behind high metal gates at the edge of town, the migrants wait their turn, not daring to leave their mud-brick compounds — the final staging post before the perilous trip across the Sahara and the sea beyond. Even neighborhood children know where they are hiding.

The migrants already bear the wounds and scars of the arduous trip, pulling up the legs of their trousers to show where they had been kicked and beaten by police, all along the line, from Senegal to Mali to Burkina Faso to Niger.

Now they have placed their lives in the hands of local “connections men,” smugglers who arrange the next leg of the dangerous passage, all the way to the Mediterranean Sea.

“I know all the tricks, how it works, from Agadez to Libya,” said a man in a brown polo shirt, speaking on the condition that only his first name, Mahamadou, be used. “When I see that people have the courage to cross the sea, I help them. That’s how I earn my living.”

This ancient desert city has been a principal departure point for Africans desperate to leave the continent for years. More than half of all West African migrants who reach Lampedusa, Italy, pass through here — up to 80,000 last year — and the International Organization for Migration expects that number to double this year.

As many as 2,000 migrants leave Agadez every week, the last big stop before reaching Libya, 620 miles away across the scorching sand. And while the government of Niger has begun cracking down on the traffic, spurred by the outcry in Europe over illegal migration, the business of moving migrants is booming.

Recent arrests, roundups and repatriations under the government’s tough new anti-trafficking law have done little to end the lucrative migrant trade in Agadez, whose permanent population is around 90,000.

Nor has the regular discovery of dozens of corpses of migrants in the desert — another 48 were found in recent weeks, victims of dehydration — stopped the flow of people north. Ten smugglers were arrested here in recent weeks, panicking migrants, 60 of whom were also rounded up, and their handlers.

But a “connections man” — the English words are used in this former French colonial outpost — can earn $50 or more per migrant, so an entire economy has revolved around them. Behind dozens of high iron gates here, in what locals call “ghettos,” the migrants are hiding, in groups of 20 to 30, waiting for the next convoy of pickup trucks across the desert.

“Many are eating off these migrants,” said a deputy mayor, Ahmed Koussa, “the drivers, the fixers, the landlords.”

Another deputy mayor, Aboubacar Ajoual, said that without even firmer action, “the Ivorians and Gambians will invade Europe.”

Streets in Agadez bustle with rare vigor for a provincial town in Niger, one of the world’s poorest nations. The market stalls are full of fresh produce, and the profusion of busy banks with working ATMs has no equal outside the nation’s capital, Niamey — all signs of the trafficking economy.

The picturesque narrow alleys of Agadez’s mud-brick Old City have been nearly abandoned by European tourists because of the threat of kidnapping and terrorism in recent years, but new construction stretches beyond the moribund airport that once received them — driven, in part, by the migrant business, international officials said.

“These are people who used to work in the tourism industry,” said Giuseppe LoPrete, head of the International Organization for Migration office in Niger. “They don’t see themselves as smugglers. For them, it’s a business.”

Furtively, groups of two or three migrants enter banks on the dusty main street for Western Union transfers, under the noses of law enforcement officers who often do not question them, despite the new law.

“The police are eating, too,” Koussa said. Payoffs to corrupt officials, as he gingerly acknowledged, along with the migrants’ fierce determination to reach Europe, continue to drive the trade.

“Here in Africa, my friend, there is no work,” said Mamadu Aliu, an unemployed truck driver from Guinea-Bissau. “We’ll work like dogs if you let us come.”

Even those at risk of arrest say the money that trafficking generates is more powerful than any crackdown on the connections men.

“It’s not the real ones who get arrested; the real ones are in complicity with the authorities,” grumbled a smuggler wearing an orange turban revealing only his eyes, who refused to give his name.

A connections man from Senegal named Mamadou, dressed in a shiny blue tracksuit that looked brand-new, unlike much of the clothing worn here, and sporting a Bluetooth headset, looked around nervously and said he did not want any trouble from authorities. His uncle had been arrested twice already, and he insisted he had left the business behind. But he was ready to point out the locations of many up-and-running “ghettos” in town.

“Many, many. You can’t even count them,” Mamadou said. Indignantly, he exclaimed: “This new law is saying what, exactly? It’s making us criminals?”

The connections men here were edgy for good reason, and not just because they faced arrest. Each link in the chain leading to Europe had to be tightly organized, they explained, because any mistake — a truck breakdown in the desert, for instance — could mean death for their charges.

“It’s all about having the good drivers, the Toubous” — a local ethnic group reputed for its toughness — “guys I’ve got confidence in,” said Mahamadou, the connections man in the polo shirt. “I turn them over to those guys. Then, I’ve got an Arab” on the Libyan side.

“The Toubou gives them to the Arab, and then the Arab gives them to my people in Tripoli,” the Libyan capital, where they can board boats for Europe, Mahamadou added. He said he had tried to migrate to Europe twice himself, only to fail. “All I do is, I facilitate the voyage, so that they can cross the desert in confidence.”

A particular frame of mind is required for the risky passage.

“It is not just about courage; it’s loss of hope,” Mahamadou said of the circumstances driving migrants to leave their homes, families and countries to undertake the perilous journey to uncertain futures in Europe, if they make it that far.

“When you lose hope, it’s better to try anything,” he said, describing himself as “the living dead” and speaking scornfully of his work, saying it was “not a proper job.”

At a so-called ghetto at the edge of town, the faces were anxious and weary. One after another, the migrants said that any risk was better than staying behind in African countries devoid of opportunity and hope.

At each leg of their journeys, they said, the police had extorted money from them. Even when they handed over the cash, they said, they were beaten.

“Back there, there is absolutely nothing,” said Sané, a migrant from eastern Senegal. “We’re leaving because we’ve got to find something for our families. We’re with God. So, we are not afraid. And, we are very tired. We’ve got to get to Europe.”

© 2015 The New York Times Company