More than 200,000 Afghans have been expelled from Iran in the past six months, marking a 25 percent increase on the same period in 2008, according to officials.
Most of the deportees are single males who had gone to Iran for employment opportunities. Hosting some 900,000 registered Afghan refugees, Iran has deported about one million Afghans considered "illegal migrants" over the past three years, according to aid agencies and government officials.
Some deportees alleged they were beaten up, incarcerated for weeks or insulted by the Iranian security forces before their expulsion.
"I was working on a construction site when the police arrested me... they beat me up with bats and then put me in a cell for three days, after which they sent me back to Afghanistan without allowing me to collect my salary and settle debts in Iran," alleged one.
Nobody at the Iranian embassy in Kabul was immediately available for comment. In the past the Iranian government has rejected allegations of violence against Afghan labour migrants.
The Afghan government, UN and other aid agencies have repeatedly called on Iran to ensure deportations take place in a humane and gradual manner. A large-scale deportation from Iran left thousands in urgent need of aid and two ministers were sacked for their failure to handle the issue in mid-2007.
"We call on Iran and other host countries not to deport Afghan migrants," Noor Mohammad Haidari, a senior adviser at the Ministry of Refugees and Returnees Affairs (MoRRA), told IRIN, adding that the situation in Afghanistan was not conducive for their reintegration.
Young men take serious risks to pay US$400-$600 to smuggling networks to travel to Iran where they seek informal jobs, often with construction companies, according to a 2008 field survey report by the International Organization for Migration.
The annual flow of remittances from Iran is estimated at $500 million, representing about 6 percent of Afghanistan's gross domestic product, according to a UN study in December 2008.
In addition, Afghanistan is a source, destination and transit route for human trafficking in South Asia, according to the Trafficking in Persons Report 2008 by the US State Department.
Women, children and men are trafficked within and outside the country for commercial sexual exploitation, forced marriage to settle debts or disputes, forced begging, debt bondage, service as child soldiers and other forms of forced labour, the report said.
Afghanistan shares a 936km-long border with Iran, a transit route for human and drug traffickers.
"The Interior Ministry must improve border control and should also do more to tackle human trafficking groups inside the country," said Haidari of the MoRRA.
Officials in the interior ministry said they were committed to stopping human traffickers and were making "significant progress".
The State Department's report stated: "The government of Afghanistan does not fully comply with the minimum standards for the elimination of trafficking; however, it is making significant efforts to do so."
This article was produced by IRIN News while it was part of the United Nations Office for the Coordination of Humanitarian Affairs. Please send queries on copyright or liability to the UN. For more information: https://shop.un.org/rights-permissions