BAYVIEW, Texas (AP) _ Maria Olivia Berrios crossed three countries, begged for food and avoided cops and robbers as she and her 16-year-old nephew, Facto Aristes, fled El Salvador.

But her thousand-mile weeklong trek that ended when she reached the Texas border Tuesday led to an immigrant detention center, not freedom.

On Thursday, she was jailed on $4,000 bail pending deportation under stringent new rules governing political asylum applications.

The Immigration and Naturalization Service refused to give further details about her case, and the status of her nephew's application could not immediately be determined Thursday by the INS.

''After all that we've been through, I can't believe we'll be turned back,'' Ms. Berrios, 33, had said late Wednesday while awaiting the decision.

She and with five other Salvadorans had talked to a reporter as they waited 100 yards from the entrance to the Port Isabel Service Processing Center, where INS officials were processing asylum applications.

''We don't want to return to El Salvador,'' where her three children remain, she said with tears in her eyes. ''There are nights we haven't been able to sleep because of all the shooting that goes on around us.

''Many people can't even go to work because of all the shooting,'' she said, biting a sweet roll and periodically setting down a small but apparently heavy bag in which she carried her belongings.

''We'll either be killed or we'll die of hunger if we go back,'' she said.

Only immigrants who can show they are victims of persecution may receive asylum; those who come to the United States solely to better themselves economically are deported.

Not one of the 51 applications processed Wednesday was accepted, the INS said. Only eight applicants were being processed Thursday morning, compared to some 50 Wednesday and 233 Tuesday, the first day that the INS implemented new rules that call for jailing of those filing claims deemed frivolous.

Asylum-seekers such as Ms. Berrios, whose applications are denied, may appeal to an INS administrative judge but must remain at the federal compound unless they can secure the $4,000 bail.

Most, like 20-year-old Freddie Marquez-Rodriguez of Managua, Nicaragua, arrived only with the clothes they're wearing and can't afford the bond.

''I came here because I did not want to go into the military in Nicaragua and now I don't know what's going to happen to my wife and children because I'm not working,'' he said.

Marquez-Rodriguez, clad in the bright orange prison uniform and wearing a green Oakland Athletics baseball cap, was one of three Central Americans detained at the federal camp who agreed to talk to reporters Wednesday.

He said he would try to get word to his wife that he was in jail and would try to get bond money from a friend in San Francisco.

''Keeping us in this jail is destroying us physically and psychologically because we want to work to bring over our families or to send them money for food and we can't get out of here,'' said Marquez-Rodriguez.

He said he went to the detention center Monday seeking asylum before the new rules took effect, but he said INS officials closed early that day.

Marquez-Rodriguez said he knew he was taking a risk when he left his wife and two small children to come to the United States.

''I had to come out of necessity,'' he said. ''All of us who came here are looking for serenity and for the same advantages for our children that children here have.''

Rosendo Lopez, a Rio Grande Valley-area missionary for the Southern Baptist Convention, was among the volunteers who operated a soup kitchen just inside the detention center. About 50 volunteers fed about 1,400 people over three days.

''We just wanted to help our fellow man. They really do want a better life and we just wanted to give them some food as they want on their way,'' Lopez said.

Because of the tighter rules and an influx of 500 immigration personnel into the area, officials believe the many Central American asylum-seekers will try to enter the country elsewhere.