Pakistani security forces have launched sweeps to arrest and deport Afghans who are in the country without papers, sending dozens back after a government-set deadline for them to leave expired.

The crackdown on undocumented migrants is mostly affecting some two million Afghans living in Pakistan without papers, though the government says it targets all undocumented or unregistered foreigners.

The campaign has drawn widespread criticism from United Nations agencies, rights groups and the Taliban-led administration in Afghanistan.

Pakistan’s interior minister said 64 Afghans were rounded up, detained and deported on Wednesday.

“Today, we said goodbye to 64 Afghan nationals as they began their journey back home,” Interim Interior Minister Sarfraz Bugti wrote on X, formerly known as Twitter. “This action is a testament to Pakistan’s determination to repatriate any individuals residing in the country without proper documentation.”

Thousands of refugees had crammed into trucks and buses on Tuesday and headed to the two key border crossings to return home to avoid arrest and forced deportation.

According to the UN agencies, there are more than two million undocumented Afghans in Pakistan, at least 600,000 of whom fled after the Taliban takeover in 2021.

Relations between Pakistan and Afghanistan’s Taliban-led administration have become strained over the past two years because of stepped-up attacks by the Pakistani Taliban, a separate militant group that is allied with the Afghan Taliban.