TIJUANA, Mexico (AP) -- As darkness fell, about 250 police officers and city workers swept into a squalid camp for migrants hoping to apply for asylum in the United States. Migrants had to register for credentials or leave. Within hours, those who stayed were surrounded by enough chain-link fence to extend twice the height of the Statue of Liberty.
The Oct. 28 operation may have been the beginning of the end for a camp that once held about 2,000 people and blocks a major border crossing to the United States. There may be more camps to come.
First lady Jill Biden sharply criticized a similar camp in Matamoros, bordering Brownsville, Texas, on a 2019 visit, saying, "It's not who we are as Americans." The Biden administration touted its work closing that camp in March, but others sprang up around the same time in nearby Reynosa and in Tijuana.
The camps, full of young children, are a product of policies that force migrants to wait in Mexico for hearings in U.S. immigration court or prohibit them from seeking asylum under pandemic-related public health powers. Uncertainty about U.S. asylum policies has also contributed to growing migrant populations in Mexican border cities, creating conditions for more camps.
Migrants are often out of public view in border cities, but the Tijuana camp is highly visible and disruptive. Tents covered with blue tarps and black plastic bags block entry to a border crossing where an average of about 12,000 people entered the U.S. daily before the pandemic. It is one of three pedestrian crossings to San Diego.
The U.S. fully reopened land borders with Mexico and Canada to vaccinated travelers Nov. 8.
Montserrat Caballero, Tijuana's first female mayor, said officials did "almost nothing" to control the camp before she took office Oct. 1. When she asked Mexico's state and federal governments to join her in erecting a fence and introducing a registry, they declined.
"The authorities at every level were scared -- scared of making a mistake, scared of doing something wrong and affecting their political careers," she said in an interview. "No one wants to deal with these issues."
Caballero said she acted to protect migrants. She knows of no homicides or kidnappings at the camp, but The Associated Press found that assaults, drug use and threats have been common.
"I could not close my eyes to the flashing red light I saw," she said. "Closing your eyes only allows it grow."
The only entry-exit is guarded around the clock by Tijuana police. Migrants with credentials are free to come and go.
"There is no asylum process (in the United States) until further notice," Enrique Lucero, the city's director of migrant services, told people who asked about U.S. policy on a morning walk-through last week.
Since March 2020, the U.S. has used Title 42, named for a public health law, to expel adults and families without an opportunity for asylum; unaccompanied children are exempt. But the Biden administration has exercised that authority on only about one of every four who come in families, largely due to resource constraints and Mexico's reluctance to take back Central American families.
It's unclear why the U.S. releases many families to seek asylum and returns others to Mexico, prompting those who are turned back to stick around until they succeed.
Mayra Funes, a 28-year-old Honduran, said she didn't get a chance to make her case to agents when she was expelled crossing the border illegally near McAllen, Texas, in March with her 7-year-old daughter. She doesn't know if she will try again after six months in the Tijuana camp.
"There is no hope of knowing how they are going to open the process," she said.
Lucero, a soft-spoken graduate of George Washington University who worked at the Mexican consulate in Chicago, says his job is persuading migrants to move to a shelter, including large facilities recently opened by Mexico's federal and state governments. Many are turned off by curfews and other shelter rules and worry being farther from the border will cut them off from news on U.S. policy changes.
Natalina Nazario, 37, needed no convincing, stopping Lucero and jumping at the city's offer to pay bus fare to Acapulco, about 1,900 miles (3,040 kilometers) away, for her and her 17- and 11-year-old sons. She fears violence in the Mexican beach city but, after a month at the camp, doesn't want her children missing more school.
Few others noticed Lucero's presence. Olga Galicia, a 23-year-old from Guatemala, sat on a curb scrubbing clothes in a plastic bin of soapy water. She had been at the camp about six months and said she will stay with her 3- and 1-year-old sons until she gets more information on how to seek asylum in the United States.
Tijuana won't forcibly remove any migrants, said Caballero, who expects holdouts to leave during seasonal rains. Thousands of migrants who came in a 2018 caravan were soaked sleeping outside in frigid November downpours.
The city estimates the camp held 1,700 people two weeks before the Oct. 28 operation, which Caballero publicly warned was coming but didn't say when.
The first count, on Oct. 29, showed 769 migrants, more than 40% children. Half were Mexican -- many from strife-torn states of Guerrero and Michoacan -- and one-third were Honduran, with El Salvadorans and Guatemalans accounting for nearly all the rest.
The steep decline just before registration likely reflects that many living there were Tijuana's homeless, not migrants, Caballero said.
The camp occupies a large, once-barren plaza. A warren of walkways includes rows that are wide enough in some parts for two people to stroll in opposite directions. People lounge inside tents or outside in folding chairs.
There are 12 portable bathrooms, 10 showers and a shared water tap for washing clothes. Charities donate food to migrants who prepare hot chocolate, fried eggs, hot dogs and spaghetti for everyone. The federal utility recently stopped the camp from stealing electricity, leaving it dark at night and forcing the makeshift kitchen to rely on canned food.
The future is less certain for a migrant camp in Reynosa, across the border from McAllen, Texas. It has about 2,000 people in a plaza near the city's main border crossing, said Felicia Rangel-Samponaro, director of The Sidewalk School, which educates children there.
The Biden administration, under a court order, plans to soon reinstate a Trump-era policy to make asylum-seekers wait in Mexico for hearings in the U.S. It hinges on approval from Mexican officials, who have told U.S. authorities they need more shelter beds and worry about violence in the state of Tamaulipas, which includes Reynosa.
The "Remain in Mexico" policy is expected to resume in "the coming weeks" after U.S. and Mexican authorities resolve "one set of outstanding issues," Blas Nuñez-Nieto, acting assistant U.S. Homeland Security secretary for border and immigration policy, said in a court filing Monday. He did not elaborate.
Caballero said U.S. authorities haven't pressured Mexico to reopen the busy pedestrian crossing between Tijuana and San Diego. U.S. Customs and Border Protection said in a statement it is working closely with Mexico "to determine how to resume normal travel safely and sustainably."
The mayor plans to ask Mexico's National Guard to help prevent camps from popping up again in Tijuana.
"The reality is that camps are going to be established if we are unprepared," she said.