Tens of thousands of US-bound refugees have been stranded in what they describe as a huge open-air prison in southern Mexico.
Refugees, who crossed the border from Guatemala, are now stranded in the city of Tapachula. which rights activist describe as a dead end for people who are waiting to get permission to continue their journey into the US.
Rights activist Luis Garcia of the Center for Human Dignification called the city "the largest immigration prison in the Americas."
Some people say they have been waiting for months to get the documents they need.
The police and military monitor the entrances and exits of Tapachula, making it almost impossible for the undocumented foreigners to leave the city.
“It's horrible here. You're trapped with no way out," said Fanfant Filmonor, a Haitian.
Around 40,000 refugees stuck in the city of 350,000 face overcrowding, inadequate healthcare and the risk of coronavirus infection, medical aid group Doctors Without Borders (MSF) said last week.
Around 200 people marched through the city into the immigration office on Wednesday to ask for documents that would allow them to head north.
Mexican security forces are accused of excessive use of force, as they have recently broken up several migrant caravans in the city.
So far this year, over 147,000 undocumented migrants have been arrested, three times more than in the same period of 2020, according to the National Migration Institute.
US authorities also arrested more than 195,000 refugees at the Mexican border in August, according to government data released on Wednesday.
Rising border crossings have created a political headache for President Joe Biden, who stands accused of inciting a chaotic migrant rush on the US border with Mexico after he vowed to unwind many of the immigration policies of his predecessor Donald Trump, when he assumed office in January.
His policies led to an influx of refugees and migrant children from South and Central America to the southern US border in recent months.
The influx of unaccompanied children at the border has become an issue for the Biden administration, which ordered to use Trump-era detainment facilities to house migrant children.
His administration is now considering resuming another controversial Trump-era program requiring asylum seekers to wait in Mexico, while their cases are processed in the United States.
Biden had condemned the harsh immigration agenda as “inhumane” and suspended it on his first day in office.
Reports said he is looking to slightly soften the policy by providing asylum seekers with better living conditions and access to lawyers. But right activists say the program endangered people’s lives by requiring them to wait in border cities plagued by criminal gangs, drugs and violence.