Pakistan on October 3 announced that 1.73 million Afghan nationals living in the country without legal documentation have a "November 1 deadline" to leave voluntarily. Since then, an estimated 374,000 people have returned to Afghanistan -- mostly in fear and haste, Philippa Candler, UNHCR representative in Pakistan, was quoted as saying in a statement issued by the UN agency on November 21.

"We are witnessing an exponential increase in arrests, detentions and deportations of Afghans in Pakistan. Mass arrivals back to Afghanistan are adding to the ongoing humanitarian crisis as winter temperatures start to dip -- in some locations the minimum already reaching -4°C," said Candler.

"Many Afghan returnees are vulnerable, including women and children who could lose their lives in a harsh winter if left without adequate shelter," she said.

UNHCR mobilizes, launches appeals

UNHCR says it has visited different locations in Pakistan in the past two weeks, meeting Afghans on the move and local authorities. Afghans interviewed in Khyber Pakhtunkhwa Province -- known as KP -- in the northwest, and Balochistan province in the southwest of the country, including registered refugees, said they were leaving in a rush, fearing arrest and detention, according to the statement.

All registered Afghan refugees are exempt from the government's orders, but the announcement and follow-up actions, including reports of intimidation by local authorities and evictions by landlords, have created a sense of panic, the UN agency noted.

The ongoing pressure to return has caused severe distress within the communities despite the assurances received from the government. "We have been reiterating our call that any return to Afghanistan should be voluntary, safe and dignified, irrespective of legal status in Pakistan," Candler was quoted as saying.

"We have urged the government of Pakistan to put in place a screening mechanism to identify individuals in need of international protection."

UNHCR says it is offering support to Pakistan to put in place a system that addresses both the concerns of the Pakistani government as well as the needs of Afghans seeking refuge on its territory.

Also read: Pakistan: Afghans facing deportation seek legal help

Focus on Afghan humanitarian crisis

UNHCR says it welcomes statements from Pakistani authorities at different levels to initiate legal actions against those who have been involved in extortion and mistreatment of Afghans who are on the move as a result of the government's order.

"We are also seeking further discussions to help address the challenges faced by Pakistan while upholding the rights of all Afghans on its territory," the official was quoted as saying.

"Those arriving now at border points inside Afghanistan are exhausted and in need of emergency assistance. Many have complained of harassment, extortion and mistreatment. Desperate women and children are among those who were not given a choice but to pack and leave."

Within Afghanistan, UNHCR and its partners are actively monitoring and providing assistance to a large number of returning Afghans at two official border crossings with Pakistan – Torkham in Nangarhar province and Spin Boldak in Kandahar province, the agency said.

"It is a daunting task on top of the ongoing humanitarian crises in Afghanistan affecting over two-thirds of the population," the statement concluded.