The district of Malashieh in Ahwaz, where one of the bombs went off, was the scene of the spontaneous demonstration that led to clashes with State Security Forces (SSF).
Two of the blasts occurred at the local governors offices in the cities of Dezful and Abadan.
The third blast occurred in Malashieh on the outskirts of Ahwaz. The city has been the scene of sporadic anti-government protests for months.
According to local residents reached by telephone, soon after the explosion in Malashieh, a large crowd spontaneously gathered at the site of the blast and began to set tyres on fire, chanting anti-government slogans.
Agents of Irans State Security Forces and anti-riot police were immediately brought in to prevent an escalation of the protest.
After anti-government demonstrations rapidly grew out of proportion last year, security forces shot dead a number of protestors from Malashieh.
At least 15 people were arrested during Mondays demonstration, as the angry crowd clashed with agents of the SSF.
Following a spate of similar bombings in Khuzestan since 2005, a string of top Iranian officials including hard-line President Mahmoud Ahmadinejad accused Britain of being behind the bombings.
London has repeatedly denied any involvement in the attacks.
