The latest crackdown on illegal aliens here sparked two days of violent demonstrations on the international bridges connecting El Paso and Juarez. The tense and emotional protest culminated in the death of a 10-year-old child and left authorities worried about continued border hostility through the summer.

The protests cut off traffic between the two cities on Friday and Saturday. American flags were thrown into the Rio Grande. Hundreds of Mexicans chanted anti-immigration slogans.

In the wake of the violence, El Paso's mayor and many Mexicans called for an investigation of what they labeled abuses of authority.

"I want an investigation by Immigration Commissioner Leonel Castillo of the way the local immigration people handled this," said El Paso Mayor Ray Salazar, who had complained to Castillo about the crackdown earlier in the week.

"My concern is the way they went about it and abused their authority. I was afraid the demonstration could spread to downtown El Paso. More people could have been hurt and property damaged. It could have had a very significant effect on our relations with Mexico."

The local director of the Immigration and Naturalization Service, Charles Perez, says his agents are only doing their job -- enforcing federal immigration laws. The protest, Perez suggested today, was an exhibition of Mexico's new-found national pride and courage from U.S. recognition of that country as a valuable fuel source.

That new pride, he said, allowed the release of pent-up hostilities toward federal and local authorities over a variety of actions taken to try to stem the tide of Mexicans crossing the border in search of work.

More than a year ago the INS blocked a popular crossing point for aliens who work in El Paso, the seldom-used Santa Fe railroad bridge. Shortly afterward the INS announced that the old, ineffective fence that guards the border between the two cities would be replaced.

Juarez taxi drivers have angrily denounced local regulations requiring them to have American insurance in order to drive tourists around El Paso.

But it was the INS crackdown Friday on Mexicans in El Paso illegally working -- many of them as maids -- that resulted in the largest protest in recent history.

The "blitz," as immigration investigators called it, began about 6 a.m. Friday. Agents arrested about 140 persons off buses in downtown El Paso. All but three, authorities said, were in the United States illegally. All were allowed to return to Juarez.

At the same time Ins/ inspectors at the downtown international bridge interviewed 105 persons, mostly women, and voided 11 three-day "shopping permit" border crossing cards. Fortysix of those interviewed had to release their permits to the inspectors until they returned with proof of a job, adequate bank account or property in Mexico.

The INS "unfortunately," Perez said, released all the persons to Mexico at the same time. The irritated returnees stopped traffic at about 10 a.m. and the protest was under way.

By noon Saturday, forces had grown to about 650 protesters at the downtown bridge and a few hundred at another bridge a few miles away.

It was there that a woman identified as an American living in Juarez, returning to El Paso, drove through the crowd of protesters, allegedly causing the death of Lara Patricia Favela Chavez. Martin Acosta Chavez, 9, and another child, who ran from the scene, were also injured. Acosta was in serious condition in a Juarez hospital today.

The driver, Carmen Candelaria de los Rios, was dragged from the car and beaten by the angry mob before being rescued by Mexican customs inspectors. Mexican authorities said the woman was held in Juarez pending charges.

A number of the female protesters charged abuses, including strip searches by male immigration inspectors. Perez denied these charges.

Protester Petra Rayso said, "It's unjust and unfair. They took our local visas so we can't cross. Now we can't work or come over to shop, either."

Another female protester said, "They treat us the same, workers or not. This happens to all Mexican women, whether they scrub floors, cook and take care of children over there or not."

Juarez taxi drivers joined the demonstrations to protest El Paso's insurance requirements.

INS's Perez said the blitzing of the buses will continue occasionally. He said it is done about 15 to 20 times a year.

"We can't yield to mob pressure," Perez said. "They were just a bunch of dissidents. This was not a confrontation between the two countries on an official basis."

Today, American flags, which had been cut from their poles atop the two bridges Saturday and thrown into the river, were flying again. A few youths lingered on the downtown bridge. Tourists traffic was minimal. Telephone calls to bridge authorities, asking about the hazards of visiting Juarez, continued throughout the day.