Pakistan has hosted Afghans fleeing violence for more than four decades, from the Soviet invasion to the 2021 Taliban takeover.

Various cohorts of Afghans have found differing degrees of stability, including access to work and education, in neighbouring Pakistan. Some were born and raised there, while others transited en route to resettlement in the West.

However, Pakistan's government, citing an uptick in violent attacks and insurgent campaigns, launched a crackdown in 2023 to evict them, painting the population as "terrorists and criminals".

More than 1.2 million Afghans have since been forced to return from Pakistan, including more than 443,000 this year alone, according to the United Nations.

The crackdown has most recently targeted an estimated 1.3 million refugees with UNHCR-issued Proof of Registration (PoR) cards, with Islamabad setting a deadline of September 1 for them to leave or face arrest and deportation.

At the Chaman border crossing, "more than 4,000 people have left ever since the deadline ended", local administrator Habib Bangulzai told AFP.

In Spin Boldak on the Afghan side, migrant registration official Abdul Latif Hakimi estimated that "250 to 300 families are returning" daily since August 31.

At the Torkham crossing further north, more than 6,300 PoR holders returned on Tuesday alone, according to authorities managing the terminal. They estimated that nearly 63,000 PoR cardholders have entered Afghanistan since April.

Afghan refugees, some awaiting relocation overseas, reported police raids as well as extortion and harassment by authorities in the lead-up to the latest deadline.

Convoys of Afghan families, fearing arrest, detention and separation, headed to the border.

The most recent data from the UNHCR shows an uptick of crossings in August, with a surge between August 24 and 30 of 25,490 Afghan returnees, of which 13,525 were PoR holders.

Afghan returnee Khan Wali told AFP he was unable to work in the eastern city of Lahore and faced constant harassment.

"Police used to detain us repeatedly. They seized our belongings," he said from the Spin Boldak crossing.

An Afghan PoR holder in Peshawar told AFP the situation was easier in that city, which borders Afghanistan and is held by Pakistan's political opposition.

However, she said "people are facing hell" in the capital Islamabad.

The latest expulsions come as already impoverished Afghanistan responds to a devastating 6.0 earthquake that wiped out villages along the border that were home to many recently expelled migrants.

More than 1,400 people were killed in the disaster.

Analysts say the evictions are designed to pressure neighbouring Afghanistan's Taliban administration, which Islamabad blames for fuelling a rise in border attacks.

The Afghan Taliban denies involvement.