A bomb tore through a military parade in Iran on Wednesday killing 12 people as the Islamic republic showcased its weaponry at events marking the start 30 years ago of the devastating Iran-Iraq war.

Among the dead were the wives of two commanders, an official said, while medics reported 81 people wounded and fearing the toll will rise.

The bomb, placed just 50 metres (yards) from the podium at the parade in the ethnically Kurdish northwestern town of Mahabad in West Ajarbaijan province, exploded at around 10:20 am (0650 GMT), officials said.

"The number of martyrs of the incident reached 12," the head of Iran's medical emergency services, Gholam Reza Massoumi, told ISNA news agency.

"So far no groups or people have claimed responsibility for this crime," deputy provincial governor Issa Ghanbari told ISNA, adding that the victims were all women except for a six-year-old boy.

Western Iran, which has a sizeable Kurdish population, has seen deadly clashes between the Iranian security forces and Kurdish rebel groups, notably the Party of Free Life of Kurdistan (PJAK), which operates from bases in neighbouring Iraq.

Provincial governor Vahid Jalalzadeh blamed the United States and "counter-revolutionaries" for the attack.

"This act has foreign origins. Unfortunately America and its allies are present in the region and their support for counter-revolutionaries and hypocrites has been proven," he said on state television.

US Secretary of State Hillary Clinton condemned the bombing, saying the attack "underscores the international community's need to work together to combat terrorism."

"I condemn the bombing targeting Iranians... and offer my sympathy to the families and loved ones of those injured and killed," Clinton said in a statement.

"The perpetrators of this attack should be brought to justice and held accountable," she added.

The bombing came as Iran showed off its military hardware at anniversary parades across the country to commemorate the 1980-88 war with Iraq in which an estimated one million people died on both sides.

The longer-range Sejil, Shahab-3 and Ghadr-1 missiles were the star attractions at the main parade in Tehran, which was attended by chief of staff Major General Hassan Firouzabadi.

With a range of 1,800 to 2,000 kilometres (1,100 to 1,250 miles), the missiles are theoretically capable of hitting Iran's archfoe Israel.

Also on display were five of Iran's Karar (Assailant) unmanned bomber aircraft, which were unveiled in August and have a nominal range of 1,000 kilometres (620 miles).

Firouzabadi insisted that Iran's arsenal was for defensive purposes only.

"The increased military capability of Iran is only a deterrent against aggressors and for defending our country against enemy threats," he said in a speech delivered before the bomb attack in Mahabad.

"We can confidently tell people that our military might is superior in the region but our military superiority is not limited to the number of planes and material calculations," he said, without elaborating.

The United States and Israel accuse Iran of seeking a nuclear weapon and have never ruled out a resort to military action to prevent it acquiring one. Iran denies any such ambition.

Iranian officials have vowed a crushing response in the event of an attack, targeting Israel and US bases in the region and the passage of oil through the Gulf.

Addressing US media in New York on Tuesday, President Mahmoud Ahmadinejad warned that attack on Iran's nuclear facilities could spark a war with "no limits."

Iran is under four sets of UN sanctions over its failure to heed repeated Security Council ultimatums to suspend uranium enrichment -- the sensitive process that can produce the fuel for nuclear power stations or, in highly extended form, the fissile core of an atomic bomb.

Russia's chief of general staff Nikolai Makarov confirmed on Wednesday that Moscow had dropped plans to supply Iran with long-awaited S-300 missiles in line with the UN sanctions.

Israel and the United States had strongly opposed delivery of the missile system because it would have made any strike against Iranian nuclear facilities far more complicated.