The unnamed men were accused of involvement in a deadly twin bombing in the oil-rich province of Khuzestan in January 2006. The province, which borders Iraq, has a large Arab population.
Dissident Arab activists in Khuzestan have accused the government of setting up trump charges against Arab activists fighting against Tehrans repressive policies.
A string of top Iranian officials, including hard-line President Ahmadinejad, have accused Britain of being behind the bombings in Ahwaz. Tehran has repeatedly accused the British secret services of training ethnic Iranian Arabs in southern Iraq and sending them to Iran to carry out sabotage operations.
London has repeatedly denied any involvement in the events in the region.
