It was a memorial for the “martyrs” killed when the U.S. struck military bases in Syria, according to Iranian state television.

A small crowd sat in rows of folding chairs, men in the front and women in the back, at the main cemetery in Tehran, the Iranian capital, earlier this month. Children milled around and a young man passed a box of sweets. A man recited prayers through a microphone.

But the 12 fallen men weren’t Iranians. They were Afghans, according to other soldiers and local media reports, part of the Fatemiyoun Brigade, a largely overlooked force that dates to the height of the Syrian civil war a decade ago. To help Syrian President Bashar Assad beat back rebel forces and Islamic State group terrorists, Iran at the time began recruiting thousands of Afghan refugees to fight, offering $500 a month, schooling for their children and Iranian residency.

The brigade is still believed to be about 20,000 strong, drawn from Afghan refugees living mostly in Iran, and it serves under the command of the Quds Force, the overseas arm of Iran’s Revolutionary Guard.

Iranian media affiliated with the Revolutionary Guard and social media platforms dedicated to the Fatemiyoun published the names and photographs of the slain Afghans and said they were killed in U.S. strikes in Iraq and Syria. The U.S. strikes were conducted in retaliation for a January drone attack on a military base in Jordan that killed three U.S. soldiers. The U.S. had blamed an Iran-backed militia based in Iraq for the attack.

Publicly, Iranian officials denied that any military personnel linked to Iran were among the casualties. Iran’s ambassador to the United Nations, Amir Saeid Iravani, told the U.N. Security Council days after the U.S. strikes that Iran had no connection to the bases attacked in Iraq and Syria. He accused the U.S. of falsely blaming Iran and said only civilians had been killed.

The guard did not issue a statement acknowledging the deaths of the Afghans under its command as it typically does when Iranian forces are killed, nor did any official threaten to avenge the deaths.

The story of the Afghan casualties, however, emerged from at least four cities across Iran — Tehran, Shiraz, Qum and Mashhad — where the bodies of the Afghans were quietly repatriated to their families, according to photos and videos on Iranian media.

At the funeral processions, the coffins of the Afghans were draped in green cloth but bore the flag of no nation. In the cities of Mashhad, Qum and Shiraz, they were carried to religious shrines for blessings.

Some mourners carried the yellow flag of the Fatemiyoun Brigade with its emblem. Local officials, clerics and a representative from the Revolutionary Guard and members of the Afghan refugee community attended some of the funerals, according to photos and videos. Two little girls wearing matching pink jackets, their hair in ponytails, wailed at their father’s coffin at another funeral on the outskirts of Tehran.