It is still unclear who was behind yesterday's bombings in Iran that killed at least eight people and injured 50 more.
Iranian officials say the bombings are aimed at stopping voters from participating in the June 17 election.
But they are calling for calm, saying such attempts at vote-sabotage are futile.
The first four blasts went off in quick succession yesterday morning in Ahvaz, the provincial capital of Khuzestan Province.
Mohammad Hussein Motahar, Iran's Interior Ministry intelligence chief, said yesterday the bombs went off within 20 minutes of each other.
"Two bombs were hidden in toilets, in the building of the Ministry of Housing and Urban Development, and at the Office of Construction and Civil Engineering. The third bomb exploded in front of the house of the governor of Khuzestan. All three of these explosions were in the city center of Ahvaz. Another bomb was hidden in the doorway of the house of a radio and television official in Ahvaz. The bomb went off when the door was opened," Motahar said.
Hours later, a smaller bomb concealed in a rubbish container exploded in Tehran, killing two people and wounding two more. News agencies have reported that two or three other bombs were also defused in the capital.
Iranian officials have alternately blamed the attacks on Arab separatists, Ba'athists, and groups backed by Western forces in Iraq.
The Interior Ministry yesterday connected the bombings to the ethnic unrest this spring in Ahvaz, in southwestern Iran close to the Iraqi border.
Riots began in April after the spread of rumors suggesting the government was planning to change the ethnic composition of Khuzestan -- a central hub of Iran's Arab minority.
Alireza Nourizadeh, a London-based journalist and director of the Center for Iranian-Arab Studies, says the bombings in Ahvaz and Tehran could in fact be related to the earlier unrest.
Five people died and some 200 were arrested during clashes in Ahvaz between Iranian Arabs and security forces.
"It was predicted that during the elections, groups that were very upset by the actions of the Iranian regime during the incidents in Ahvaz would take action, first to reinforce their presence, and also to tell the regime that it can't put a cover on events that led to the death of several Iranian Arabs and also to the arrests of many people. Therefore, these events can be connected to each other," Nourizadeh said.
Three Groups Claim Responsibility
It is unclear who is behind the bombings.
Rahim Fazilatpour, deputy governor of Ahvaz, told Iran's Student Agency (ISNA) that three Arab groups had claimed responsibility for the bombings.
Other sources have reported that a separatist group called The Revolutionary Martyr Guards of Al-Ahvaz had claimed responsibility for the Ahvaz attacks.
A spokesman for Iran's National Security Council, Ali Agha Mohammadi, told the "Shargh" daily that foreign movements were involved in the attacks.
Some observers believe Iranian hard-liners could have orchestrated the blasts themselves in order to gain political authority ahead of the presidential vote.
Nourizadeh, however, disputes such claims.
"There is some suspicion that some of the explosions could have been caused by elements within the establishment in order to create a militarized atmosphere during the elections. [It is possible] that some of the security organs of the Revolutionary Guard or parallel security organs would take such measures, but I think they would only go to the point of having the incident end with a loud [explosion]. When it comes to casualties, one can't with confidence link them to the blasts," Nourizadeh says.
Nourizadeh adds that the explosions may focus increased attention on at least one candidate -- Mohammad Baqer Qalibaf, who is a former police chief:
"There is some talk going on in the higher echelons of the establishment that the country needs a powerful government. The presence of Mr. Qalibaf [as a presidential candidate] is a result of these arguments. If people currently feel concerned about their security, it is possible the regime will use it to encourage people first to participate in the elections, and also to vote for Mr. Qalibaf, who had been successful as a member of the security forces," Nourizadeh says.
Iranian President Mohammad Khatami today ordered all security personnel to speed up investigations to identify the perpetrators behind the explosions.
Golnaz Esfandiari joined RFE/RLs News and Current Affairs Department as a correspondent in December 2004.