TEHRAN, 13 June 2005 — One person was killed and four were injured in an explosion in central Tehran yesterday, state-run television reported, hours after four bombs targeted at government buildings in southwest Iran killed at least eight and injured 36.

Tehran blamed “terrorists” and Arab separatists “sheltered by US troops in neighboring Iraq” for the series of blasts in the capital and the southwestern city of Ahvaz.

The Popular Democratic Front of Ahvaz, which is campaigning for an independent Khuzestan, denied it was behind the attacks, but said another Arab group calling itself the Ahvazi Revolutionary Martyrs’ Brigades had claimed responsibility.

State-run radio said the Tehran blast, which occurred near Imam Hussein Square in the city center, was caused by a bomb.

At least four women were among those killed in the explosions in Ahvaz, capital of the southwestern Khuzestan province bordering Iraq.

The blasts were the deadliest explosions in Iran in more than a decade.

Gholamreza Shariati, deputy provincial governor for security affairs, said perpetrators were seeking to undermine public participation in Friday’s presidential elections.

Television footage showed heavily damaged buildings and blood on the ground. The force of the explosions also damaged many cars in the streets.

Shariati said 36 people, including eight police officers, were injured in Ahvaz.

Following the first three blasts, experts had tried to defuse a fourth bomb but failed, and it exploded, injuring one of them.

The explosions follow recent violent protests in Ahvaz over alleged plans to alter the proportion of Arabs and non-Arabs in the region.

Amir Hossein Motahar, director of security at the Interior Ministry, said one bomb went off in front of the Ahvaz governor’s office and another next to the city’s housing department. The third bomb blew up in front of the residence of the head of the provincial radio and television station, he said. The fourth bomb, which experts failed to defuse, was placed near the same residence.

Two of the four bombs were car bombs, witnesses said.

Shariati said intelligence and security officers were trying to determine the cause of the explosions but said the target of the explosions was “Iran’s territorial integrity as it was on the verge of presidential elections.”

About 150 demonstrators protested outside the governor’s office in the evening, waving Iranian flags and chanting “Death to the hypocrites” — a term used for the exiled opposition People’s Mujahedeen Organization.

Ahvaz was the site of two days of violent demonstrations in April after reports circulated of an alleged plan to decrease the proportion of Arabs in the area. Officials at the time confirmed one death but opposition groups said more than 20 demonstrators had been killed. Some 250 were arrested.

The protests were sparked after copies of a letter allegedly signed by Vice President Mohammad Ali Abtahi circulated in the area. The letter ordered the relocation of non-Arabs to Ahvaz to make them the majority population. Abtahi denied writing the letter.

Khuzestan contains the vast bulk of Iran’s 132 billion barrels of proven oil reserves, the world’s second largest.

Arabs make up about 3 percent of Iran’s population; Persians account for 51 percent of the population of 69 million.

Bomb explosions have been a rare occurrence in Iran since the end of the 1980-88 Iran-Iraq war.

The attacks came ahead of Friday’s presidential election that opinion polls indicate Ali Akbar Hashemi Rafsanjani is likely to win. But he remains well short of the 50 percent support he needs to avoid a run-off vote.

A poll published Saturday showed that Mostafa Moin, one of three reformists in the race, had edged ahead of former police chief Mohammad Baqer Qalibaf into second place.