HERAT, AFGHANISTAN — Tears streamed down her cheeks as she held up the pictures of her two grandsons. Both of them, Sayed Mujtaba and Sayed Ismail, were in the Afghan army a couple of years ago. When the Islamic State started gaining ground in Syria, Iran used its religious influence with Shi’ites in neighboring countries, like Afghanistan, to get volunteer fighters.

Mujtaba and Ismail were two of the many who answered the call. Then last year, Qamar Bibi received news that they had died fighting. One of them left a young wife and a little child behind.

“Since 2013, Iran has supported and trained thousands of Afghans…to fight in Syria,” according to a report by the Human Rights Watch that came out in October this year.

They even have their own unit, a group that an Iranian newspaper close to the government, Kayhan, described as “the Fatemiyoun Brigade for Defense of the Holy Shrines, made up of devout Afghan Muslims.” Some reports suggest the unit has since been elevated to a division.

Tasnim News Agency, an Iranian government affiliated news agency, also described the Fatemiyoun as “an all-Afghan unit.”

According to a recent report by the New York Times, members of the Fatemiyoun division “wear a shoulder patch recounting words of praise from Iran’s supreme leader as a badge of honor.”

Recently, Afghanistan’s Deputy Chief Executive Officer, Haji Mohammad Mohaqiq, stirred controversy when, during a trip to Tehran, he praised fighters, including Afghans, who participated in the war in Syria against the IS. This was the first time a senior level Afghan official had acknowledged that Iran enlisted Afghans, possibly thousands of them, for participation in the Syrian conflict.

Mohaqiq also reportedly praised Major General Qasim Soleimani, the head of the Islamic Revolutionary Guard Corp’s international Quds force. The Iranian general is supposed to be one of the founders of the Fatemiyoun Division.

Many of the recruits for the unit came from the more than two million Afghan refugees that have been living in Iran for decades. However, others, like Mujtaba and Ismail, left from Shi’ite dominated areas of Afghanistan.

While the Afghan foreign ministry maintains that it is investigating reports of Iran sending Afghans to fight in Syria or Iraq, an influential warlord and former governor of Herat province, Ismail Khan, believed it was common knowledge in his region.

“Many families have brought back bodies of those killed in Syria and held their funerals here. It has been frequently reported in local media. An Iranian leader even had a meeting with the families who lost men in the Syrian war,” Khan said.

The Afghans going to fight often went willingly. According to Bibi, her grandsons were so eager to go, they left despite their family’s opposition.

“Their parents, all of us, we begged them not to go, but they said they were going to defend our holy sites. They left secretly, first to Iran and from there to Syria and called us from there to tell us they were there,” she said.

The two Shi’ite Afghans fought in Syria for two years. Their funeral was held in the Iranian city Mashhad. Bibi said the graveyard, called Bahisht-e-Raza, was large and full of graves of people who died in Syria.

The government of Iran paid for the funeral and arranged for their father to visit Karbala in Iraq, one of Shi’ite Islam’s holiest sites. Bibi did not know if their family has received any other help, but they still live in Iran.

In Shi’ite-dominated Heart province, where Iran’s cultural influence could be seen all around, locals said recruitment for the war in Syria was done openly. Shi’ite clerics in the region often used their pulpits to encourage locals to join the fight in Syria, in order to defend their holy sites against groups like the Islamic State.

However, with the IS in Afghanistan claiming several large scale attacks against the Shi’ites, and trained Shi’ite fighters returning home, the possibility of a sectarian conflict in the country could not be ruled out.

“There was always talk about that; the commander would say that one day you will go defend in your own country,” one of the returning Afghan fighters told the New York Times.

Additionally, the war in Syria is winding down, and tensions between Sunni Saudi Arabia and Shi’ite Iran are increasing internationally. Afghan officials worry the returning Afghan fighters could also become proxies in a battle between the two regional rivals.