Five bomb explosions took place in Iran on Sunday, killing ten people and injuring nearly 40, five days ahead of the presidential elections.
The latest explosion occurred at the Shohada-Safa juncture near the Imam Hussein Square in central Tehran at about 20:20 local time (15:50 GMT) when a small bomb went off, killing at least two people and wounding four others, state media said.
The official IRNA news agency quoted residents as saying that shortly after the blast police and fire fighters arrived at the scene and there might be another bomb set nearby.
"Police are trying to defuse a bomb," a witness said.
Tehran's explosion came just several hours after four bombs blew up in the southwestern Iranian city of Ahvaz, killing eight people and injuring scores.
The explosions in Ahvaz, capital of the oil-rich Khuzestan province bordering Iraq, took place near four crowded locations separately, including the governor's office, a civilian residence center, a public service agglomerate with some financial institutions and a governmental organizations' center, a source told Xinhua by phone.
It has not been proven yet that the Tehran explosion is related to those in Ahvaz.
The serial explosions happened just 5 days ahead of Iran's ninth presidential elections.
Gholam Reza Shariati, deputy governor of Khuzestan, told state television after the four explosions in Ahvaz that the explosions were aimed to damage the country's integrity and undermine the elections.
"We cannot say for now who were behind the attacks, and it is still under investigation, but certainly they cannot reach their aim of spoiling the elections," Shariati said.