A group of weary women sort through a suitcase of used clothes in the shady yard of a migrant shelter close to the US border, while their infants breastfeed or nap on makeshift beds and older children take turns playing on a brightly painted slide.

Most of the 60 or so women staying at the Madre Assunta Scalabrini nun’s shelter in Tijuana are on a rapidly expanding list waiting to be allowed to seek asylum with their children across the border in San Diego, where they remain hopeful that US authorities will take pity on them.

Ana Ramírez, 34, arrived here 12 days ago from the violent coastal city of Acapulco in southern Mexico, with three children aged 11 to 17 and her 18-month-old grandson. They fled after armed men threatened to kill the family unless the oldest boy – a 14-year-old high-school student – agreed to sell drugs for their gang. The same men took away three of his classmates, who have not been seen since.

Ramírez reported the threat to authorities, who advised the family to leave. Terrified, they abandoned their house, clothes, toys, her hotel job and the children’s schooling and borrowed money to fly to Tijuana. On Tuesday, the family was 400th in the asylum queue – down from more than 1,000 12 days ago.

‘If we go back they will kill us all’

Ramírez, like most of women here, was unaware of the new curbs on victims of gang violence and domestic abuse announced last week by the US attorney general. Asylum is for people fleeing persecution because of their religion, political beliefs or membership in a social group, Jeff Sessions said, not those fleeing crime.

Ramírez had come prepared with a police report, which she believed would persuade US immigration authorities to grant asylum. “I have proof, if we go back, they will take my son or kill us all, I’m trying to keep my family together … I’m seeking asylum, I wouldn’t enter illegally.

Children play at the Madre Assunta shelter in Tijuana Photograph: Nina Lakhani

Before Donald Trump said on Wednesday he would end the practice, the number of children separated from their parents by his administration as part of its zero-tolerance tactic to deter migrants and asylum seekers was rising fast. Most of the families ripped apart are from Central America’s northern triangle – El Salvador, Honduras and Guatemala – ranked the most dangerous region in the world outside an official war zone.

Amnesty International has said the practice amounts to torture under international law. There is no coherent plan for reuniting the families.

Kirstjen Nielsen, secretary of homeland security, denied that families seeking asylum through legal entry points were being separated. But 14 of 17 asylum-seeking parents recently interviewed by Amnesty who were forcibly separated from their children had entered the US legally.

Ramírez had heard rumours that Honduran children were being separated from their parents, but only those over the age of 14. Shown some of the images to emerge in recent days of children in cages, she started to cry and hugged her grandson close. “I won’t let that happen, I’ll turn back.”

Some have heard nothing about the unfolding controversy. Laura Ruíz, 18, from Copan, Honduras was nursing her two-year-old son who could barely keep his eyes open. They arrived after a gruelling journey, and had not seen any news or heard anything about what has been going on a few miles across the border. They planned cross irregularly, with the baby’s father who was staying at the men’s shelter next door. “We’re so close, we have to try.”

Many of the women interviewed by the Guardian remained hopeful, encouraged by stories of relatives and friends who in recent months and years were given a chance to claim asylum: exactly the “loophole”the Trump administration says it is seeking to close.

‘What would you do?’

Esther Castro, 21, was travelling with her tiny but boisterous two-year-old daughter, and could not stop crying due to a mix of exhaustion, desperation and piercing back pain that she does not have the money to treat.

The single mother from Michoacán has been severely depressed since being raped when she was 17. A flurry of anonymous callers in the past few weeks threatened to rape her and her daughter. She was so scared, she packed a few things and left.

“I’m going to tell them my story, just like I told you, and have faith in God that they will let us pass … If they try to take my daughter, I’ll turn back, I won’t let them.”

According to experts consulted by the Guardian, it is unclear if turning back would be permitted, and would likely depend on nationality, point of entry and availability of detention facilities.

In an average year, Madre Assunta hosts 1,200 women or children. But in the first five months of 2018, the number rocketed to 1,560. In a complete turnaround from last year, about 80% were Mexican, mostly from the embattled states of Guerrero and Michoacán where armed groups control everything from the drug markets to avocado farms. The others mostly come from Central America, a few from African countries including Sudan and the Democratic Republic of the Congo.

Last year was Mexico’s most violent year on record with almost 30,000 murders. The murder rate is up 20% so far in 2018.

Many at the border are willing to risk potential separation in the US over guaranteed violence at home.

Mary Galvan, social worker at Madre Assunta, was horrified by the new US policy and angered by the Mexican government’s slow condemnation.

“He [Trump] is the anti-Christ. But put yourself in these women’s shoes and imagine you had to choose between staying home and being killed, or crossing the border and risk your children being put into cages and treated savagely, but where there’s a tiny bit of hope. What would you do?”

