MATAMOROS, Mexico (AP) — Migrants rushed across the border hours before pandemic-related asylum restrictions were to expire Thursday, fearing that new policies would make it far more difficult to gain entry into the United States.

In a move to clear out overwhelmed holding facilities, Border Patrol agents were told Wednesday to begin releasing some migrants with instructions to appear at an immigration office in the United States within 60 days, according to a US official. The official was not authorised to speak publicly about the matter and provided information to the Associated Press on condition of anonymity.

The Biden administration has been unveiling measures to replace Title 42, which suspended rights to seek asylum since March 2020 on grounds of preventing the spread of COVID-19.

On Wednesday, the Homeland Security Department announced a rule to make it extremely difficult for anyone who travels through another country, like Mexico, to qualify for asylum. It also introduced curfews with GPS tracking for families released in the US before initial asylum screenings.

In Matamoros, across from Brownsville, Texas, migrants arrived steadily on Wednesday, stripping down before descending a steep bank clutching plastic bags filled with clothes. They slowly waded into the river, one man holding a baby in an open suitcase on his head.

On the US side, they put on dry clothing and picked their way through concertina wire. Many surrendered to authorities, hoping to be released to stay legally while pursuing their cases in backlogged immigration courts, which takes years.

William Contreras of Venezuela said Title 42 was favourable to people of his wracked South American country, having heard that many before him were released in the United States.

“What we understand is that they won’t be letting anyone else in,” said Contreras’ friend, Pablo, who declined to give his last name because he planned to cross the border illegally. “That’s the reason for our urgency to cross through the border today.”

The Border Patrol stopped about 10,000 migrants on Tuesday, one of its busiest days ever, according to a US official who spoke on condition of anonymity because he was not authorised to speak publicly. That’s nearly double the daily average of about 5,200 in March, the latest publicly available data, and close to the 11,000 that US officials have predicted is the upper limit of a surge they anticipate after Title 42.

More than 27,000 people were in US Customs and Border Protection custody, the official said, well above capacity. In March 8,600 were in custody.

Border Patrol agents were ordered Wednesday to begin releasing migrants in any border sector that reached 125 per cent of its holding capacity with instructions to report to an immigration office within 60 days. They were also told to start the releases if the average time in custody exceeded 60 hours or if 7,000 migrants were taken into custody across the entire border in any one day.