Pakistan's deadline for undocumented foreigners to leave has expired, as more than 140,000 migrants, mostly Afghans, are estimated to have left voluntarily.
Authorities rounded up people and took them to temporary holding centres ahead of last night's deadline, set a month ago, to leave or face expulsion.
Some who have spent decades in Pakistan crammed into trucks queued on the border.
The sudden expulsion threat came after suicide bombings this year that the government said involved Afghans, without providing evidence.
Pakistani authorities said Afghan nationals were found to be involved in attacks against the government and the army, including 14 of this year's 24 suicide bombings.
Islamabad has also blamed them for smuggling and other militant attacks as well as petty crimes. Afghanistan rejects the accusations.
Pakistan has brushed off calls to reconsider its decision from the United Nations, rights groups and Western embassies, who have urged it to incorporate into its plan a way to identify and protect Afghans facing the risk of persecution at home.
The vast majority of undocumented foreigners in Pakistan are Afghans, and, while authorities have not yet provided official data, only a few would comprise people from Iran and some central Asian countries, among others.
Pakistan is home to more than four million Afghan migrants and refugees, about 1.7 million of them undocumented, Islamabad says, although many have lived in Pakistan for their entire lives.
About 600,000 Afghans have crossed into neighbouring Pakistan since the Taliban took over in 2021, joining a large number there since the Soviet invasion of Afghanistan in 1979 and the ensuing civil wars.
Islamabad says deportation will be orderly, carried out in phases and start with those who have criminal records.
Authorities have threatened raids in areas suspected of housing "undocumented foreigners".
Afghanistan's Taliban-run administration has dismissed Pakistan's accusations against Afghan migrants.
It has asked all countries hosting Afghan refugees to give them more time to prepare for repatriation.
"We call on them not to deport forcefully Afghans without preparation, rather give them enough time and countries should use tolerance," the administration said in a social media post on Afghans in Pakistan and elsewhere.
It assured Afghans who have left over political concerns that they could return and live peacefully in the country.
