BEIRUT, Lebanon — Afghan immigrant children as young as 14 are being recruited in Iran to fight — and die — in Syria, a prominent human rights organization said Sunday.

The group, Human Rights Watch, said it had verified the deaths of eight Afghan children in Iran, who were recruited and ultimately died fighting for the Fatemiyoun division in Syria, by inspecting tombstones in cemeteries in Iran, cross-referencing them against the names of fighters reported dead in Iranian news reports, and by speaking to the families of several of the teenagers.

The Human Rights Watch report demonstrates that Afghan fighters younger than 18 have died in Syria, and it sheds new light on the recruitment of Afghan Shiites to fight in Syria, where Iran backs the Syrian government in a multisided war. Iran is home to many Afghans, who have traveled there to work or as refugees fleeing conflict in their country. Human rights groups have long expressed concern that vulnerable Afghan refugees are being pressured by the Iranian authorities to fight in Syria.

More graves for teenage fighters are believed to exist, Human Rights Watch says, citing reports of fighters’ deaths in the Iranian news media. According to the group’s report, some of the children’s epitaphs identify their place of death as Syria, while some tombstones bear the inscription “defender of the shrine” — a reference to Sayyida Zainab, an important shrine in Syria revered by the Shiite sect of Islam, to which many Afghans and Iranians belong.