Mexico City ? Sidling up to migrants who arrive at the Tijuana airport and cruising the streets in border towns, “coyotes” in gold chains and dark sunglasses openly find customers for nightly scrambles across the U.S. border.

Mexico’s president offered to crack down on smuggling at a recent summit with President Bush. But close to 100 smuggling gangs still are operating, government officials say, in plain sight of Mexican law enforcement.

“While drug smugglers are invisible for the most part, people smugglers are visible, working right in front of authorities,” said Tijuana border expert Victor Clark, who has studied the illegal trade for decades.

Smuggling people into the United States from around the world has become a $10 billion-a-year industry, according to U.S. Immigration and Customs Enforcement officials. Global crime networks use Mexican smugglers to sneak in Cubans, Brazilians, Iraqis, Africans and Chinese, according to Interpol, the international police network.

Border experts say the price for Mexican migrants has quadrupled from $300 to more than $1,200 since 1994, when the U.S. last tightened the rules. The price is higher for migrants from Central and South America – Brazilians said they pay $10,000 to $15,000 for a package that includes airfare to Mexico City and passage across the border into the U.S.

President Vicente Fox’s administration has been caught between promoting itself as the migrants’ protector and bowing to U.S. pressure to crack down on gangs sneaking migrants across the border.

An unidentified man who acts as a guide for immigrants crossing the Rio Grande from Nuevo Laredo, Mexico, to Laredo, Texas, walks along the river's edge waiting for clients in this Oct. 26, 2001, photo. Hoping to encourage Washington to legalize millions of migrants, Mexico's president has offered to crack down on a multimillion-dollar network that smuggles migrants from around the globe into the United States.

Although smugglers have been blamed for abandoning some migrants to their deaths in the desert heat, the Mexican government has been hesitant to move against them, knowing the death toll would climb if people crossed on their own, Clark said.

“Migrant traffickers have become a necessary evil,” he said.

Corruption also taints Mexico’s efforts to stop human trafficking. Clark, who heads the Tijuana-based Binational Center for Human Rights, said his group interviewed 50 detained smugglers and found 39 of them actually were migrants who were handed over to authorities after the real smugglers paid off police.

Human trafficking is not a priority for Mexican politicians more concerned with kidnappings, drug trafficking and murders, border experts say. Officials from five federal government entities, including the presidency, did not respond to repeated requests for comment for this story over several days.

Since taking office in December 2000, Fox has sought the passage of a migration accord as the centerpiece of his administration. Bush also expressed enthusiasm for such a measure until his attention turned to border security after the Sept. 11, 2001, attacks.

At the summit last month in Cancun, Fox once again told Bush he would do more to prosecute smugglers, hoping to encourage Washington to legalize millions of migrants. Fox noted that his government already had strengthened enforcement on Mexico’s southern border to stem the flow of U.S.-bound Central Americans.

But he made clear that Mexicans would not be stopped from heading to the border, because their right to travel within Mexico is constitutionally guaranteed. “We can’t infringe upon the right of people to move freely within our territory,” Fox said.

Critics say Mexico is using that argument as an excuse to turn a blind eye.

In one example, they point to Las Chepas, a smugglers’ haven near the New Mexico border that Mexico tried to wipe off the map last September by bulldozing a third of its houses. Six months later, the smugglers were back and doing better than ever, working daily, untouched by police.