Iranian citizens in Sistan-Balochistan, a province bordering Afghanistan, took to the streets on Friday, demanding the right to water that flows from Afghanistan, according to Iranian State media Irna.
According to Khaama Press, security forces intervened after protesters started attacking Afghan trucks.
Reports say Iranian protesters broke the windows of trucks and caused financial loss to their drivers.
A second group of Iranian protestors rally outside the Afghan consulate in Zahedan city and demand that Helmand water be taken to Iran.
Afghanistan's drivers demanded a refund of their losses after the demonstration of Iranian nationals.
Ashraf Ghani, the former Afghan president, inaugurated a hydroelectric dam-Kamal Khan Dam- on the Helmand River a year ago after telling Iran it wouldn't be given free water, but in exchange for oil.
For years, the flow of the Helmand River into Iran has been a source of dispute between Afghanistan and Iran that is still unresolved after the war in Afghanistan began.