Afghan officials on May 3 launched an operation to locate and retrieve bodies of migrants from a river in western Herat Province after reports that Iranian border guards had thrown Afghans into the river to prevent their entry into Iran.
In a statement on May 2, the Afghan Foreign Ministry said a probe had been launched into the reports.
It was not immediately clear how many migrants had been involved in the alleged incident, which was denied by the Iranian consulate in the region.
A senior official in the presidential administration said initial assessments suggested at least 70 Afghans who were trying to enter Iran from Herat were beaten and pushed into the Harirud River.
Doctors at Herat District Hospital said they had received the bodies of five Afghan migrants, some of whom had drowned.
"Of these bodies, it's clear that four died due to drowning," said Aref Jalali, head of Herat District Hospital.
Provincial council member Ahmad Karokhi said that 12 people were able to swim to safety, adding that seven bodies have been recovered from the river in the Gulran district of Herat.
Afghan citizen Noor Muhammad told Reuters he was one of 57 Afghan citizens who were caught by Iranian border guards on May 2 when they were trying to cross into Iran from the Gulran district.
"After being tortured, the Iranian soldiers threw all of us in the Harirud River," Mohammad told Reuters, adding that the group was in search of work.
Another man from the group, Shir Agha, said he also survived but that at least 23 of the 57 people thrown by Iranian soldiers into the river were dead.
The Iranian Consulate in Herat denied the allegations.
"Iranian border guards have not arrested any Afghan citizens," the consulate said in a statement on May 2.
Iranian Embassy officials in the Afghan capital, Kabul, were not immediately available for comment.
Afghan officials in the area say this was not the first time that Afghans had been tortured and killed by Iranian security forces guarding the 920-kilometer border.
The incident comes as the coronavirus outbreak has seen a mass return of Afghan migrants from Iran, one of the global pandemic hotspots, with many returnees testing positive for the virus.
Decades of conflict, extreme poverty, and high rates of unemployment force thousands of Afghans to illegally cross the border to Iran every year.
There are currently up to 1 million registered Afghan refugees in Iran, while the country hosts another 2 million undocumented Afghans, according to UN reports.