HERAT, Afghanistan (AP) — Tens of thousands of Afghans recruited, paid and trained by Iran to fight in support of Tehran's ally President Bashar Assad are returning to their homeland, as the 8-year war in Syria winds down.

Most of them are from Afghanistan's impoverished Shiite communities and were attracted by the promise of relatively high pay in Iranian-run militias.

Iran has run an extensive drive to bring Shiites from across the region and create a network of militias to help save Assad from the uprising against his rule — not only Afghans but also Pakistanis, Iraqis and Lebanese.

The Afghan government and many experts believe Iran could mobilize these ex-fighters once more to assert its influence in Afghanistan, particularly as the United States accelerates its efforts to end its nearly 18-year military intervention.