The blast occurred minutes after 10 am inside one of Ahwazs banks. The ceiling of Saman Bank collapsed and parts of it were set ablaze, the banks manager told state-run news agencies.
The head of the Medical Faculty of the citys university announced that at until now there had been at least eight confirmed fatalities and 46 injuries.
The state-run news agency ISNA quoted the citys governor, Mohammad Jafar Samari, as saying that six people had died in the blast.
A second blast was caused by a sonic-boom at the Natural Resources Organisation.
The Iranian government previously blamed ethnic Arabs in the province for a spate of bombings in Ahwaz that rocked the city in the aftermath of extensive clashes between security forces and anti-government protesters.
Al-Manar television, run by Lebanese Hezbollah, reported that the attacks were targeting Iranian President Mahmoud Ahmadinejad. The report said that after learning of possible attacks, Ahmadinejad cancelled his trip.
